Synthesis of Cinnamaldehyde from Benzaldehyde

Vidallon, Mark Louis P. Date Per word form February 20, 2012 CHEM44. 1 2LDate Submitted March 12, 2012 MIXED-ALDOL CONDENSATION synthesis of Cinnamaldehyde I. Introduction Cinnamaldehyde, cinnamic aldehyde or 3-phenyl-2-propenal is the major constituent of cinnamon bark anele, extracted from several species of genus Cinnamomum (C. verum, C. burmanii, C. cassia), under the family Lauraceae, a conference of ever commonalty trees. Cinnamon bark (particularly C. verum) effects 0. 4-0. % oil, which checks 60-80% cinnamaldehyde, 4-5% sesquiterpenoids (? -humulene, ? -caryophyllene, limonene and others), eugenol, cinnamyl acetate, eugenol acetate, cinnamyl alcohol, methyl radical eugenol, benzaldehyde, benzyl benzoate, cuminaldehyde, monoterpenes (linalool, pinene, phellandrene and cymene), safrole and others (List and Horhammer Masada Ravindran qtd. from Khan and Abourashed, 2011). Isolation of cinnamaldehyde from cinnamon oil of Cinnamomum sp. ark, called quills, quillings, feathe camps and chips depending on forest, was scratch do in 1834 by Dumas and Peligot (Attokaran, 2011). It has been proved that cinnamaldehyde from cinnamon oil has a very(prenominal) high capableness in the pharmaceutical industry, past from its thoroughly known role in the food preparation, specifically as spice, odorant and assumptionant. several(prenominal) researches have be the antimicrobial activity of cinnamaldehyde against Salmonella typhimurium and Bacillus subtilis (Council of Europe, 2008).Also, cinnamaldehyde has been turn out to inhibit microbial growth of opportunistic human pathogenic fungus kingdom, much(prenominal) as Aspergillus niger, Candida albi wads and Rhizopus oligosporus, and various bacteria (Escherichia coli, Enterobacter cloacae, Micrococcus luteus, Staphylococcus aureus, strep faecalis, and others) (Khan and Abourashed, 2011). Several studies have also unraveled the hypoglycemic (insulin-like) and hypolipidemic properties of cinnamaldehyde sinc e it preserve cause expansive glucose oxidation and uptake, causing go down in blood plasma glucose levels rock-bottom glycosylated hemoglobin, serum total cholesterol and riglyceride levels increased plasma insulin, hepatic animal starch and high-density lipoprotein and restored modified plasma enzyme concentrations to almost normal level (Babu, Prabuseenivasan and Ignacimuthu, 2006). Though impressive approaches in the isolation of cinnamaldehyde from cinnamon oil from quills, low meats of pure cinnamaldehyde place only be retrieveed from salutary separation processes.Feature Article sexual intercourse RatesFree-Radical BrominationDue to this demarcation in the disc everywherey and investigation of other potential medicinal and non-medicinal set of cinnamaldehyde, chemists have also developed man-made operations to obtain high kernels of pure cinnamaldehyde, one of which is the mixed aldehyde-alcohol condensate of benzaldehyde and ethanal. mix aldol condensi ng is a response of antithetical aldehydes or ketones leadership to the formation of aldols (? -hydroxyaldehydes) or ketols (? -hydroxyketones), come with by the removal of urine to dissolvent finally to enals (? , ? -unsaturated aldehydes) or enones (? , ? -unsaturated ketones).Aldol extensions are delinquent to the reception of enolate ions of cytosineylic chemical compounds (from the reaction of mordantic ? -enthalpys of aldehydes and ketones with bases) with the electrophilic centers of other carbonyl compounds. Synthesized aldols and ketols hobo dehydrate spontaneously or toilette be dehydrated, especially when heated, to form enals and enone, the final intersection school principal(s) of aldol compressions (Moore and Langley, 2010). achievable side reactions were the Canizzarro reaction of benzaldehyde and the self- contraction of ethanal. Minimization of the possibilities of the give tongue to reactions was make by pursual a special scheme of role.Ch aracterization evidences that were through with(p) in to confirm the personal indistinguishability of the proceedss are grinding picture aspiration, reactions with nitric acid and with sodium bisulfite and derivatization with 2,4-dinitrophenylhydrazine. In the experiment conducted, the objectives of the author were as follows 1. To synthesize cinnamaldehyde from the base-catalyzed mixed aldol condensate of benzaldehyde and acetaldehyde and 2. To remember the synthesized harvest-time using its turn point, results of transparent chemical tests and derivatization reactions, on with the determination of the elting points of the hydrazones and comparison of the hydrazones using their RGB values. II. Materials and Methods A. Reagents The side by side(p) are the reagents were use in the experiment Benzaldehyde acetaldehyde 15% sodium hydrated oxide settlement atomic number 11 chloride 95 % fermentation alcohol origin 40% sodium bisulfite theme 2, 4-dinitrophenylhyd razine Nitric acid Ice B. Apparatus and Equipment The quest are the machine and equipment were employ in the experiment 50-mL round-bottom flask 50-mL beaker 10-mL graduated cylinder 10-mL pipet Pasteur pipet Micro di unchanginging flask examen tubes Evaporating dish Thermometer etna burnerMicroreflux Watch glass fight ring Iron clamp Iron stand Separatory funnel Wire gauze Hot plate electronic top loading balance Fisher-Johns dissolve point instrument III. ceremonious Diagrams C. Synthesis of Cinnamaldehyde (in round-bottom flask) 3. 06mL sang-froid in ice bath + 3. 00mL 15% NaOH + 0. 50mL dropwise with swirling + 3. 00mL 15% NaOH + 0. 50mL dropwise with swirling + 3. 00mL 15% NaOH + 0. 68mL dropwise with swirling reflux for 10-15 minutes cool to room temperature cool in ice bath separate layers entire layer , very minimal (in 10-mL graduated cylinder) Aqueous layer very minimal, unreactedH2O with Na+ and Cl- broadside amount and save for delineation discard D. Characterization 1. Boiling evince Determination point of intersectionion (in di freeing flask) distill nonee temperature at which liquid starts to boil 2. reception with Nitric Acid (Test for presence of benzene ring) 1-2 drops of test compound1 (in test tube) + 1-2 drops HNO3 get hold visible changes and temperature changes 3. Reaction with Sodium Bisulfite (Test for presence of carbonyl compounds) 4. 0mL 40% NaHSO3 + 1. 0mL ethanol filter Resi callable Filtrate Save and label spiritous NaHSO3 1-2 drops of test compound1 (in test tube) + 1-2 drops downpour NaHSO3Observe visible changes 4. Derivatization with 2, 4-Dinitrophenylhydrazine 1-2 drops of test compound1 (in test tube) + 4. 0mL ethanol + 3. 0mL filter recrystallize using 95% ethanol Colored hydrazone crystals Determine break up point and RGB values Compared appearance, thaw points and RGB values with other hydrazones 5. conflagration Test 2-4 drops of test compound1 (in evaporating dish) flame carefully using Bunsen burner flame Observe flammability, flame change and eroticainess and compared with other test substances 1 Compounds to be tried are cinnamaldehyde (product), benzaldehyde and acetaldehyde.IV. Data and Results dining table 1. Observations on the synthesis of cinnamaldehyde. Reagent/ action mechanism Taken Observations Benzaldehyde Clear, colorless, dense liquid ethanal Clear, colorless liquid Sodium hydroxide Colorless liquid Benzaldehyde + NaOH White mixture Mixture + dropwise addition of acetaldehyde Yellow oil (upper layer) and off- colour visit layer wane Dark brownish, opaque, viscous liquid mixture Cooling Formation of layers origination Organic layer (Upper) Dark brown, opaque viscous liquid with cinnamon scent Aqueous layer (Lower) Light brown, translucent liquidProduct Dark brown, opaque viscous liquid with cinnamon scent remand 2. Percent collapse of the synthesis of cinnamaldehyde. Compound Amount (mL) Benzaldehyde 3. 06 Acetaldehyde 1. 68 Cinnamal dehyde Theoretical 3. 78 Experimental 3. 46 % permit 91. 6 % Table 3. Boiling points of compounds used and synthesized in the experiment. Compound Boiling point (oC) Benzaldehyde 179 Acetaldehyde 65-82 Cinnamaldehyde Theoretical 250-252 Experimental Decomposed Table 4. Results of the characterization tests of the product and reactants. Compound Reaction with HNO3 Reaction with NaHSO3 Observations (+/-) Observations (+/-) Benzaldehyde Yellow- orangish liquidHeat production + White precipitate + Acetaldehyde Clear, colorless liquid (N. R. ) White precipitate + Cinnamaldehyde Two layers opaque, dark brown (upper) and translucent, chocolate brown (lower) + Brown precipitate + Table 5. Results of the derivatization with 2,4-DNP. Compound Observations resolve point of hydrazone (oC) Mean RGB determine (in hexadecimal) Theoretical Experimental Benzaldehyde chromatic lily-livered solids 255. 25 218 E7B01A Acetaldehyde Crimson red solids 221. 6 174 C75B34 Cinnamaldehyd e Red orange solids 267. 76 Decomposed AF6D21 Table 6. Observations on the combustion test of the reagents and the product. Compound Flammability flame up color Sootiness Benzaldehyde Flammable Orange Sooty Acetaldehyde fair flammable patrician Very sooty Cinnamaldehyde Very flammable Orange Extremely sooty with b omit resiimputable Sample Calculations V benzaldehyde = gram molecule benzaldehyde ? MW benzaldehyde ? 1/? benzaldehyde V benzaldehyde = (0. 03 mol)(106. 12 g/mol)(1. 00 mL/1. 0415 g) V benzaldehyde = 3. 06 mL V acetaldehyde = mol acetaldehyde ?MW acetaldehyde ? 1/? acetaldehyde V acetaldehyde = (0. 03 mol)(44. 05 g/mol)(1. 00 mL/0. 788 g) V acetaldehyde = 1. 68 mL Theoretical yield = mol cinnamaldehyde ? MW cinnamaldehyde ? 1/? cinnamaldehyde Theoretical yield = (0. 03 mol)(132. 16 g/mol)(1. 00 mL/1. 05 g) Theoretical yield = 3. 776 mL %Yield = (3. 46 mL/3. 776 mL) ? 100% %Yield = 91. 6% Maximum sacking by solvation V cinnamaldehyde = ? cinnamaldehyde ? solubility in H2O ? V urine V cinnamaldehyde = (1. 00 mL/1. 05 g)(4. 09? 10-4 g/mL)9. 00 mL+(0. 030 mol)(18. 016 g/mol)(1. 00 mL/g) V cinnamaldehyde = (1. 00 mL/1. 05 g) (4. 09? 0-4 g/mL)(9. 54 mL) V cinnamaldehyde = 3. 72? 10-3 mL % discharge by solvation = (V cinnamaldehyde lost/ Theoretical yield) ? 100% %Loss by solvation = (3. 72? 10-3 mL/3. 776 mL) ? 100% %Loss by solvation = 0. 098% V. Discussion Cinnamaldehyde, cinnamic aldehyde or 3-phenyl-2-propenal is the sovereign grammatical constituent of cinnamon oil, extracted from several species of Cinnamomum (C. verum, C. burmanii, C. cassia), under the family Lauraceae, a group of evergreen trees. Cinnamon bark (particularly C. verum) yields 0. 4-0. 8% oil, which contains 60-80% cinnamaldehyde (List and Horhammer Masada Ravindran qtd. rom Khan and Abourashed, 2011), which was first isolated in 1834 by Dumas and Peligot (Attokaran, 2011). It has been proven that cinnamaldehyde from cinnamon oil has a very high potency in the field of medici ne, aside from its well known role in the cooking and baking, specifically as spice, odorant and colorant. Several researches have explained and proven the anti-diabetic properties of cinnamaldehyde (Babu, Prabuseenivasan and Ignacimuthu, 2006) also, studies have shown the antimicrobial activity of cinnamaldehyde against Salmonella typhimurium and Bacillus subtilis (Council of Europe, 2008).Cinnamaldehyde has been proven to inhibit microbial growth of opportunistic human pathogenic fungi and various bacteria (Khan and Abourashed, 2011). Though effective approaches in the isolation of cinnamaldehyde from cinnamon oil from quills, low amounts of pure cinnamaldehyde female genitalia only be obtained from effective separation processes. Due to this demarcation in the discovery and investigation of other potential medicinal and non-medicinal values of cinnamaldehyde, chemists have also developed synthetic procedures to obtain high amounts of pure cinnamaldehyde, one of which is the mixe d aldol condensation of benzaldehyde and acetaldehyde.The synthesis of cinnamaldehyde through mixed-aldol condensation was done by mixing, in a cooled microreflux, benzaldehyde, portions of 15% sodium hydroxide resolvent and acetaldehyde, added in a dropwise manner, and and so refluxing the mixture for 15-20 minutes. Isolation of the synthesized cinnamaldehyde was done entirely by separating the water water-insoluble cinnamaldehyde layer from the aqueous layer. Aldol condensation is the reaction of aldehydes and/or ketones star to the formation of ? -hydroxyaldehydes (aldols) or ? hydroxyketones (ketols), also known as the aldol addition, accompanied by the removal of water molecule ( dehydration) from these compounds result finally to enals (? , ? -unsaturated aldehydes) or enones (? , ? -unsaturated ketones) (Moore and Langley, 2010 McMurry and Simanek, 2008 Fox and Whitesell, 2004). Aldol additions are overdue to the reaction of enolate ions of carbonyl compounds (from the reaction of acidic ? -hydrogen atoms of aldehydes and ketones with bases) with the electrophilic centers of other carbonyl compounds. vaporisation, which croupe be spontaneous due to formation of a much conjugated system or promoted by heating, then leads to the generation of the ? , ? -unsaturated carbonyl compounds as the final product of the aldol condensation (McMurry and Simanek, 2008 Fox and Whitesell, 2004). Aldol condensations tummy be classified as simple and mixed-(or cross-) aldol condensation. The difference between the two classifications is that simple aldol condensation utilizes only one aldehyde or ketone substrate while the mixed-aldol condensation uses two assorted carbonyl compounds as the substrate for the reaction (Fox and Whitesell, 2004).The mixed-aldol condensation was type of reaction employed in the experiment however, simple aldol condensation, also known as self-condensation was one of the expected side reactions in the conducted study. The general eq uation for the synthesis of cinnamaldehyde was The mechanism of the synthesis reaction can be proposed as 6. Formation of ethenolate ion nucleophile 7. Aldol addition Formation of 3-hydroxy-3-phenylpropanal 8. Dehydration Formation of cinnamaldehyde The initial step done in the experiment was feature 3. 06 milliliter benzaldehyde with three 3. 0 milliliter portions of 15% sodium hydroxide with dropwise addition of 1. 68 milliliter acetaldehyde while swirling the mixture, which was in the microreflux, lordotic in an ice bath. Benzaldehyde, followed by 3. 00-milliliter portion of 15% sodium hydroxide solution, was first come in into the microreflux kind of of the acetaldehyde to prevent acetaldehyde from undergoing self-condensation with the following general equation Compared to acetaldehyde, benzaldehyde has no 3 ? -hydrogen atoms, which can react with the nucleophile, hydroxide ions, to form a strong nucleophile, the ethenolate ion.Ethenolate ions can struggle acetaldehyde ins tead of attacking benzaldehyde. Thus, benzaldehyde, which can remain as it is in sodium hydroxide, was put in first until the formation and attack of the nucleophile, which was form right later on acetaldehyde was dropped into the reaction mixture. The following is the mechanism of the self-condensation of acetaldehyde, which was belittled by the procedure carried out Addition of 3. 00-milliliter portions of 15% sodium hydroxide solution, a snub base, was done to compensate for the combination of benzaldehyde and sodium hydroxide, before adding acetaldehyde.Benzaldehyde reacts with strong, concentrated bases to form benzenecarboxylate and hydroxymethylbenzene this is known as the Canizzarro reaction. Canizzarro reaction (mechanism shown below) was calumniated by the addition of the strong base in small portions, before adding the acetaldehyde, and using a edit solution of it. Cooling of the mixture in ice bath was done to favor the reaction aldol condensation of benzaldehyde an d acetaldehyde, a spontaneous reaction due to the higher(prenominal) item of legal jointure of the product, while disfavoring the self-condensation of acetaldehyde, a heat-requiring reaction (Fox and Whitesell, 2004).Dropwise addition of the enolizable compound, acetaldehyde, was performed to minimize the drastic formation of ethenolate ions while unreacted acetaldehyde molecules still exist in the mixture. The phenomenon was prevented since it would have entailed the self-condensation of acetaldehyde, which could have caused lower yield in the experiment since the reagent would have been consumed in the unnecessary reaction just showd. The microreflux was shake while the mixture was still being prepared to distri unlesse the ethenolate ions formed though the mixture for them to react with the electrophile, benzaldehyde.This procedure was also done to minimize the possibility of the self-condensation of acetaldehyde since the ethenolate ions generated were expected to have react ed with benzaldehyde since they were distributed with the aid by palpitation before the next drop of acetaldehyde came in contact with mixture. Further much, since the reaction mixture was icy, the reaction was expected to be slow olibanum, shaking can compensate for the slow movement of molecules and ions in the mixture by in some manner contributeing the energy needed for the slow-moving benzaldehyde molecules and ethenolate ions to collide.Refluxing was done to (1) react the still unreacted benzaldehyde molecules and ethenolate ions and (2) promote the dehydration of the 3-hydroxy-3-phenylpropanal to finally form the 3-phenyl-2-propenal or the cinnamaldehyde. Refluxing intimately mixes substances by increasing the contact between the reactant particles through boiling and evaporation, followed by the condensation in the reflux condenser (due to the removal of heat by the cold water flowing in the condenser) and restoration of the synthesized compound and the little (expected) amount of the unreacted reagents on their original vessel (Mayo, Pike and Forbes, 2001).Refluxing the mixture was very profitable to the conducted experiment since it ensured higher yield and faster dehydration of the 3-hydroxy-3-phenylpropanal, though the stated reaction was expected to be spontaneous due to the higher degree of conjugation of the product (3-phenyl-2-propenal) compared to the 3-hydroxy-3-phenylpropanal. The synthesized cinnamaldehyde was readily separable (solubility of cinnamaldehyde in water=4. 09? 10-4gram/milliliter) with the lower aqueous layer however, cooling of the mixture was done first to decrease the solubility of the cinnamaldehyde to achieve higher recruitable amount of the product.Liquid-liquid extraction to recover the solvated cinnamaldehyde was not done since the maximum amount of solvated cinnamaldehyde was just 0. 098% of the theoretical yield (see Sample Calculations), thus the recovery of such little amount of product would be wasteful in te rms of effort and reagents. Graduated cylinder was used directly as the receiver of the organic layer stray to determine right away the amount of synthesized cinnamaldehyde. The determination of the amount of product in this kind of manner was performed to minimize the loss of products due to the affixation of the very viscous product on the sides of different containers.The amount of the synthesized cinnamaldehyde was gear up to be 3. 46 milliliter, 91. 6% of the theoretical yield which was computed as 3. 776 milliliter. practical sources of error in the experiment were the losses of minimal amount of reagents due to their adherence on the sides of the Pasteur pipets and 50-milliliter beakers and the losses of the synthesized cinnamaldehyde caused by its adhesion on the sides of the microreflux, place of the boiling chip and the inside surface of the separatory, caused by the high viscosity of cinnamaldehyde.The lack of however purification process on the cinnamaldehyde, which could still contain traces of benzaldehyde, acetaldehyde and other side products, could also be a factor, atomic number 82 to the incorrectness of the results of the experiment. The synthesized cinnamaldehyde was expected to be constituted of the cis- and trans- diastereomers however, it was expected that the trans-isomer was the major component of the product. The reason for the claim was that higher possibility of existence of its trans-isomer-forming transition state strain compared to the cis-isomer-forming transition state residence.Elimination to a trans double attach from the staggered conformation of the 3-hydroxy-3-phenylpropanal transition state, wherein the carbonyl group and the phenyl group are in the anti position to minimize the steric effects on the molecule, was still favored, though the carbonyl group is relatively small, compared to the energetically less stable gauche conformation (due to steric interactions of the carbonyl group and the large phenyl group) of the 3-hydroxy-3-phenylpropanal, which can cause the cis-isomer formation (Carey and Sundberg, 2001). (a)(b) presage 1.Balls and sticks representation of 3-hydroxy-3-phenylpropanal in the conformations for the formation of (a) trans-cinnamaldehyde and (b) cis-cinnamaldehyde. Carbon 2 shadows carbon 3 to show the anti-conformation in (a) and the gauche conformation in (b) of the phenyl and the carbaldehyde groups. Further trial impression that the formation of the trans-cinnamaldehyde was favored in the reaction was the coplanar arrangement of the highly conjugated aldol condensation product. According to Fox and Whitesell (2004), extended conjugation of the benzene ring with the alkene double bond and carbon-type O double bond of the carbonyl group in the ? ? -unsaturated aldehyde product leads to the horizontal, coplanar arrangement of the product. The p orbital overlap of extensive ? system of the carbonyl group and the alkene is greatest as the ? systems arrange in a single plane, which leads to higher stability of the molecule in terms of the conjugation present. Having a flat product would cause the increased torsional strain on the molecule due to the very close distance of the carbonyl group and the benzene ring. Therefore, cis-benzaldehyde, minded(p) the stated situation, is highly unstable and is not preferentially formed over trans-benzaldehyde. (a) (b) Figure 2.Balls and sticks representation of (a) trans-cinnamaldehyde and (b) cis-cinnamaldehyde, viewed at different perspectives to show the differences in the languor of the two molecules that contribute to their stabilities. Possible side reactions in the experiment conducted were the self-condensation of acetaldehyde and Canizzarro reaction as previously stated a eagle-eyed with the preventive measures exercised to minimize their occurrence. Self-condensation of acetaldehyde was expected to be greatly minimise by the procedure employed and the fact that it is energetically unfavorable, ac cording to Fox and Whitesell (2004).Furtherto a greater extent, even if the reaction withalk place, it would have been very minimal since it is a reversible reaction, which was competed with a more favorable reaction that is followed by an irreversible somehow spontaneous dehydration reaction. Depletion of the ethenolate ions (due to the consumption in the addition of benzaldehyde and ethenolate ions, then conversion of the intermediate to cinnamaldehyde) causes the competing self-addition of acetaldehyde to proceed backwards, forming back the acetaldehyde and ethenolate ions, which can be consumed in the aldol condensation of cinnamaldehyde and acetaldehyde.Simple distillation was done to determine the boiling point of the synthesized cinnamaldehyde however, rot was observed in the middle of the procedure, causing the failure of the melting point determination attempt but supported that it was possible that cinnamaldehyde. The observed annihilation can be attributed to the insta bility of cinnamaldehyde, usually denoted by thickening and decomposition, when exposed for a long time to air at elevated temperatures but lower than its boiling point (70C) (Gholivand and Ahmadi, 2008).Decomposition of natural cinnamaldehyde, however, is not observable in baking and cooking due to the presence of eugenol impurities on cinnamon oil, which has antioxidative properties that harbor cinnamaldehyde from heat-induced decomposition (Cinnamaldehyde mental object). The chemical tests performed were reaction with nitric acid, formation of the sodium bisulfite addition complex and derivatization with 2, 4-dinitrophenylhydrazine.Reaction with nitric acid is a test for the specialization of aromatic and aliphatic aldehydes. Aromatic aldehydes undergo nitration with concentrated nitric acid under normal conditions. collateral test results can are color changes and/or heat production. The general equation for the nitration of aromatic aldehydes is Results of the reaction with nitric acid were shown in Table 4. Figure 3. Test results for the reaction of nitric acid with acetaldehyde (left), benzaldehyde (middle) and cinnamaldehyde (right).Positive test results were observed with benzaldehyde and with cinnamaldehyde by the production of biased mixtures, yellow and brown, respectively, accompanied by heat production as shown by the following specific mechanism 1. Formation of nitrosonium ion 2. Electrophilic addition of the nitrosonium ion to the aromatic aldehyde (a) Cinnamaldehyde Ortho attack Para attack (b) Benzaldehyde (Meta attack) (c) Acetaldehyde Reaction with alcoholic sodium bisulfite solution is a confirmatory test for aldehydes and ketones, having the following reaction and mechanism mechanicsResults of the reaction of the compounds with alcoholic sodium bisulfite solution were listed in Table 4. Positive results were observed with acetaldehyde, benzaldehyde and cinnamaldehyde, which were denoted by the formation of transparent accumulation wh ich turned to white precipitate, white precipitate and brown precipitate, respectively. Figure 4. Test results of the reaction of alcoholic sodium bisulfite with cinnamaldehyde (left), benzaldehyde (middle) and acetaldehyde (right). Sodium bisulfite addition complexes were the observed precipitates of the following reactionsDerivatization with 2, 4-dinitrophenylhydrazine was done to support the identity of the cinnamaldehyde by the determination of the melting point of the hydrazone formed in the derivatization since the boiling point of the cinnamaldehyde was impractical to measure wedded that it is relatively high and the product, being impure can undergo decomposition. Derivatization with 2, 4-dinitrophenylhydrazine was performed by licentiousness the test compound (cinnamaldehyde, acetaldehyde and benzaldehyde) in 4. 00 milliliter of ethanol and adding 3. 0 milliliter 2, 4-dinitrophenylhydrazine solution. The formed precipitate was then filtered and then recrystallized using stripped amount of 95% ethanol solution. The general equation and the mechanism of the reaction can be proposed as Mechanism Results of the derivatization, with 2, 4-dinitrophenylhydrazine, were shown in Table 5. The following are the equations for the derivatization of each aldehyde with 2,4-DNP in the experiment Colors of the derivatives obtained were qualitatively different due to the differences in their degrees of conjugation.Decomposition of the cinnamaldehyde hydrazone was observed, which hindered the determination of the melting point of the hydrazone. Deviations from theoretical melting point values of the two other hydrazones were observed on the data-based melting points gathered. The observed discrepancies maybe ascribed to the aptitude of the Fisher-Johns melting point apparatus and/or the quality of the reagents (benzaldehyde, acetaldehyde and 2, 4-dinitrophenylhydrazine) used.To compensate for the failure in the melting point determination of the cinnamaldehyde hydra zone, the RGB (Red, Blue, Green) values or the web color keywords used by computer monitors to generate colors (McFarland, 2009), of the three hydrazones were determined and time-tested for significant differences using Analysis of variant (ANOVA). Figure 5. Isolated and purified hydrazones of benzaldehyde (left), acetaldehyde (middle) and cinnamaldehyde (right). Mean RGB values obtained for cinnamaldehyde, acetaldehyde and benzaldehyde were shown in Table 5.Results of the Analysis of Variance revealed significantly differences among the red values and among the green values of the three hydrazones and no significant differences among the blue values of the hydrazones. Having significantly different values on at least one of the RGB values proves that the composition of the hydrazones was significantly different, thus implying that the probable presence of benzaldehyde and acetaldehyde in the product was negligible and that cinnamaldehyde can be the compound present.Results of the combustion test were shown in Table 6. Combustion is a chemical reaction between a substance and oxygen that proceeds with the evolution with heat and light as flame (Stoker, 2009). It can be complete, where all of the substance totally undergoes combustion with carbon dioxide and water as the product (general) or neither, caused by several factors, which brings about carbon monoxide and elemental carbon formation (soot).Observed differences in the sootiness of acetaldehyde, benzaldehyde and cinnamaldehyde were due to the differences in the number of carbon atoms and the differences in the degrees of unsaturation of the molecules of each of the compounds. Incomplete combustion is in the main observed in long chain hydrocarbons and other organic compounds given that oxygen is limited (Johnson, 1999 Macomber, 1996) since oxygen is consumed along with the carbon of the organic compound to produce carbon dioxide while hydrogen atoms are utilized, also along with oxygen, to produce w ater.Furthermore, unsaturated organic compounds (having as much carbon-carbon double bond) favors incomplete combustion since the number of carbon atoms is relatively higher than the number of hydrogen atoms excess carbon atoms cannot be used up in the combustion process to produce carbon dioxide (when oxygen supply limited) and thus soot forms (Lister and Renshaw, 2000). It has been show in the balanced equations of the combustion each compound that cinnamaldehyde requires the highest amount of oxygen, followed by benzaldehyde and, lastly, by acetaldehyde.Given that, in the combustion test conducted, oxygen supply was almost uniform among the three, soot formation was predicted to be observed more prominently on cinnamaldehyde (product), followed by benzaldehyde and lastly by acetaldehyde due to the amount of carbon atoms and the relative number of unsaturations on each molecules. The identical arrangement was also the experimental arrangement of the compounds with respect to the observed degrees of sootiness after the carried out combustion test.The structure of cinnamaldehyde was supported by the controlling reaction of cinnamaldehyde with nitric acid and with alcoholic sodium bisulfite. Though it can be inferred that the detected compound can also be benzaldehyde, the cinnamaldehyde color (yellow to brown), viscosity and the cinnamon aroma of the compound (which are qualitatively different from the color, viscosity and odor of benzaldehyde), the characteristic decomposition of cinnamaldehyde below its boiling point and the results of the combustion test can be used as further evidence of the identity of the compound produced.Possible sources of error in the experiment were the quality of the reagents used, intervals of drop acetaldehyde on the mixture, lack of further purification process, lack of more evident tangible and chemical characterization method for the product, efficiency of the melting point apparatus utilized and the storage of cinnamaldeh yde product for too long prior to derivatization. I. Summary and ConclusionThe special synthesis experiment, entitled Mixed-Aldol ejector seat Synthesis of Cinnamaldehyde, was conducted to synthesize cinnamaldehyde from the base-catalyzed mixed aldol condensation of benzaldehyde and acetaldehyde and characterize the synthesized product using its boiling point, results of simple chemical tests and derivatization reactions, along with the determination of the melting points of the hydrazones and comparison of the hydrazones using their RGB values.The synthesis of cinnamaldehyde through mixed-aldol condensation was done by mixing, in a cooled microreflux, benzaldehyde, portions of 15% sodium hydroxide solution and acetaldehyde, added in a dropwise manner, and then refluxing the mixture for 15-20 minutes. Isolation of the synthesized cinnamaldehyde was done simply by separating the water insoluble cinnamaldehyde layer from the aqueous layer. Determination of the tidy sum of the synthe sized substance was then performed.Chemical test carried out were test for aromatic ring (reaction with nitric acid), test for aldehydes (reaction with alcoholic sodium bisulfite) and derivatization with 2, 4-dinitrophenylhydrazine while the physical characterization test done were boiling point determination using simple distillation and melting point determination of the derivatized hydrazones. RGB values of the isolated and recrystallized hydrazones were obtained and tested for significant differences using Analysis of Variance (ANOVA). It was shown that positive test results were exhibited by cinnamaldehyde and benzaldehyde in their reactions with nitric acid.It was also shown that positive test results were displayed by cinnamaldehyde, benzaldehyde and acetaldehyde in their reactions with alcoholic sodium bisulfite. The boiling point of the isolated product and the melting point of the cinnamaldehyde hydrazone were not obtained due to the decomposition of the stated compound. H owever, RGB values of the hydrazones were obtained. Results of the Analysis of Variance of the RGB values of the hydrazones revealed significantly differences among the red values and among the green values and no significant differences among the blue values of the hydrazones.Based on the results, it can be concluded that that synthesized product was different from the starting materials and that it was possible that the product was cinnamaldehyde due to the highly colored hydrazone formed. Though chemical tests were successfully done, boiling point determination of the product and melting point determination of its hydrazone were unsuccessfully performed due to the decomposition of both product and its hydrazone however, chemical tests done and physical properties exhibited by the compound were considerable as enough indicant of the identity of the compound.Based on the readily perceivable physical characteristics of the compound produced and the results of the chemical tests perf ormed and observed, it can be concluded that the synthesized compound was genuinely cinnamaldehyde. Based on the results of the experiment, it was proven that cinnamaldehyde, constituted primarily of trans-cinnamaldehyde, with a percent yield of 91. 6%, was successfully synthesized using the described procedure of the student.Furthermore, the procedure constructed and performed was proven to have minimized the possible side reactions which could have impeded the yield, physical properties and authenticity of the penalize chemical tests. Possible sources of error in the experiment were the quality of the reagents used, intervals of dropping acetaldehyde on the mixture, lack of further purification process, lack of more evident physical and chemical characterization method for the product, efficiency of the melting point apparatus utilized and the storage of cinnamaldehyde product for too long rior to derivatization. II. References ABOURASHED EA and KHAN IA. 2011. Leungs Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. Germany J. Wiley and Sons. 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USA University Science Books. MAYO D, expressway R. and FORBES, D. 2001. Microscale Organic Laboratory With Multistep and Multiscale Syntheses. USA John Wiley and Sons, Inc. MCFARLAND, DS. 2009. CSS The Missing Manual. 2nd Ed. USA OReilly Media Inc. MCMURRY J and SIMANEK E. 2008. Fundamentals of Organic Chemistry. 6th Ed. Singapore Thomson Learning. MOORE JT and LANGLEY RH. 2010. Organic Chemistry II for Dummies.USA Wiley Publishing. STOKER S. 2009. General, Organic and Biological Chemistry. USA Cengage Learning. Cinnamaldehyde Content Foods Determined Gas Chromatography-Mass Spectrometry. Retrieved from APPENDIX A Randomly Selected RGB Values of Different Hydrazones Table 7. Sample RGB values of acetaldehyde, benzaldehyde and cinnamaldehyde hydrazones and their mean values. Sample No. Acetaldehyde Benzaldehyde Cinnamaldehyde Red Green Blue Red Green Blue Red Green Blue 1 202 90 52 203 168 25 185 10 7 22 2 189 85 50 239 170 17 173 106 53 3 195 97 58 233 185 25 185 114 22 4 206 ci 54 236 171 43 174 102 18 5 199 80 40 232 176 19 173 109 37 6 201 81 57 236 181 29 174 123 40 7 201 99 59 236 179 28 170 103 24 8 198 92 42 232 178 18 164 105 45 Mean Values (decimal) 199 91 52 231 176 26 175 109 33 Mean Values (hexadecimal) C7 5B 34 E7 B0 1A AF 6D 21APPENDIX B Analysis of Variance (ANOVA) of the RGB Values of the Hydrazones ruby-red Source DF SS MS FC FTAB treatment 2 12682. 75 6341. 375 90. 76086216 3. 466800112 Error 21 1467. 25 69. 86904762 Total 23 14150 GREEN Source DF SS MS FC FTAB Treatment 2 32406. 08 16203. 04 328. 5193 3. 4668 Error 21 1035. 75 49. 32143 Total 23 33441. 83 BLUE Source DF SS MS FC FTAB Treatment 2 2888. 083 1444. 042 1. 039985 3. 4668 Error 21 29158. 96 1388. 522 Total 23 4899. 958