Caproic Acid Synthesis

In this lab, caproic piercing was synthesized in a multi-plod manner that implicated the contrive of three compriseds – diethyl n-butylmalonate, potassium n-butylmalonate, and n-butyl malonic piercing respectively. An IR was used to distinguish the starting esthetic, n-bromobutane, and the principal comprised, diethyl n-butylmalonate; while IR and NMR were used to distinguish the definite issue, caproic piercing. Reactions, Agency and Theory Caproic piercing a. k. a n-hexanoic piercing is a carboxylic piercing ascititious from hexane which has the unconcealed contriveula C5H11COOH.It is a snowy pulchritudinous fluent delay a truly piercing trail associated delay goats. Caproic piercing was synthesized in a multi-plod manner which executed three compriseds - diethyl n-butylmalonate, potassium n-butylmalonate, and n-butyl maonic piercing. The contrive of caproic piercing implicated alkylation, saponification, and decarboxylation reactions. The principal comprised, diethyl n-butylmalonate – a diethyl ester of malonic piercing – was synthesized via an alkylation reaction. Alkylation reactions include the structure and alkylation of an enolate. In this lab, NaOEt, a cogent grovelling was used to drag off one of the most piercingic ? hydrogens of the carbonyl ester – diethylmalonate – to contrive an enolate. In adjust to alkylate the alpha posture which now has a denying load, the enolate was used to assault an alkyl halide, 1-bromobutane via Sn2 agency. The agency for the aloft reaction is shown under: The promote comprised, potassium n-butylmalonate, was synthesized by saponification of the principal comprised, diethyl n-butylmalonate, delay potassium hydroxide. The hydrolysis of diethyl n-butylmalonate resulted in the structure of potassium n-butyl malonic piercing by losing the ethoxy collection (-OCH2CH3) from twain sides of the carbonyl ester.Further deprotonation of the contriveed piercing by -OCH2CH3 contrives a carboxylate, potassium n-butylmalonate. The agency for the aloft manner is shown under: N-butyl malonic piercing, the third comprised, was forthdelay synthesized from the potassium n-butylmalonate by the protonation of potassium n-butylmalonate via the adduction of extravagance HCl as shown under: The definite plod of this lab implicated the decarboxylation of n-butyl malonic piercing to contrive caproic piercing. Decarboxylation is the non-location of a carboxyl collection, -COOH, from a carbonyl junction to contrive CO2 and an enol which raise tautomerizes to contrive a ketone.In this lab, the non-location of a -COOH from the n-butyl malonic piercing contriveed 1,1-dihydroxy-hex-1-ene. Tautomerization of this issue leads to the structure of caprioc piercing. the aloft reaction agency is shown under: Reagent Tables Consultation 1: Contrive of diethyl n-butylmalonate (Reagents and Product) Name| Chemical Formula| Molecular Weight| Density(g/ml)| Conc(M)| Amount(g or ml)| Amount(moles)| Melting Point(0C)| Effervescence Point(0C)| Sodium Ethoxide| NaOEt| 68. 05| 0. 868| | 50ml9. 1187g| . 134| 260| ---| Diethyl malonate| | 160. 17| 1. 055| | 20. 34ml21. 46g| . 134| -50| 199| 1-Bromobutane| n-BuBr| 137. 2| 1. 270| | 14. 5ml18. 36g| . 134| 1. 2686| 101. 4| Absolute Ethanol| EtOH| 46. 07| 0. 789| | 35ml| | -114. 3| 78. 4| Ether| Et2O| 74. 12| 0. 7134| | | | -116. 3| 34. 6| Water| H2O| 18. 1| 1000| | | | 0| 100| Magnesium sulfate| MgSO4| 120. 415| 2. 66| | | | 1124| ---| Diethyl n-butylmalonate| C11H20O4| 216. 28| 0. 983| | | | ----| 235 -240| Consultation 2: Contrive of Potassium n-butylmalonate (Reagents and Product) Name| Chemical Formula| Molecular Weight(g/mol)| Density(g/ml)| Conc(M)| Amount(g or ml)| Amount(moles)| Melting Point(0C)| Effervescence Point(0C)| Diethyl n-butylmalonate| C11H20O4| 216. 8| 0. 983| | | | ---| 235 -240| Potassium hydroxide| KOH| 56. 11| 2. 044| | | | 420| 1327| Water| H2O| 18. 1| 1000| | | | 0| 100| Sodium Chloride| NaCl| 58. 443| 2. 165| | 35ml| | 801| 1413| Potassium n-butylmalonate| | | | | | | | | Consultation 3: Contrive of n-Butyl malonic Piercing (Reagents and Product) Name| Chemical Formula| Molecular Weight(g/mol)| Density(g/ml)| Conc(M)| Amount(g or ml)| Amount(moles)| Melting Point(0C)| Effervescence Point(0C)| Potassium n-butylmalonate| | | | | | | | | Hydrochloric piercing| HCl| 36. 46| 1. 180| | | | -27. | 110| Ether| Et2O| 74. 12| 0. 7134| | | | -116. 3| 34. 6| Magnesium Sulfate| MgSO4| 120. 42| 2. 66| | | | 1124| ----| n-Butyl malonic piercing| C7H12O4| | | | | | | | Consultation 4: Contrive of Caproic Piercing (Reagents and Product) Name| Chemical Formula| Molecular Weight(g/mol)| Density(g/ml)| Conc(M)| Total (g or ml)| Total (moles)| Melting Top (0C)| Effervescence top(0C)| n-Butyl Malonic Acid| C7H12O4| 160. 17| ----| | | | 102-105| ---| Caproic Acid| C6H12O2| 116. 16| 0. 920| | | | -3| 202-203|Procedure: * Contrive of Diethyl n-butylmalonate (IV) 0mL of NaOEt and a magnetic marked bar were adventitious to a dry 250mL circular gsmooth flask disposed delay a condenser, a calcium chloride arefaction tube, and a separatory funnel which was unshaken to the institute using a Claisen adapter. 20. 34mL of diethyl malonate was adventitious to the reredisconnection via the separatory funnel balance a epoch of encircling fifteen minutes. Next, 35mL of EtOH and 14. 5mL of n-BuBr were adventitious to the conformation respectively. The reredisconnection was overflowed for 10 minutes using a heating bubble and then cooled on ice. The aloft conformation was posterior poured into 200ml of impart and then epidemic to a 500mL separatory funnel. 0mL of ether was used to gather the conformation principal and then 20mL of ether each was used to gather the aqueous lamina indelicate past times. The radical laminas were then fully and dried delay MgSO4. The conformation was filtered and then evaporated to ~100mL. The definite reredisconnection was then epidemic to a 250mL circular gsmooth flask and single life was carried out. Behind ether and ethanol had distilled off, the diethyl n-butylmalonate was attentive. When the life latitude reached ~90, the manner was stopped and the synthesized diethyl n-butylmalonate was stored in the circular gsmooth flask.An IR of the starting esthetics, diethyl malonate and n-BuBr, and the issue diethyl n-butylmalonate were run. * Contrive of potassium n-butylmalonate The diethyl n-butylmalonate was epidemic to a insignificant separatory funnel and a condenser, excite bar, Claisen adapter and the separatory flask was unshaken to the 250mL life flask. A reredisconnection of 30g KOH in 30mL of impart was disposed and this reredisconnection was adventitious to the life flask. ~5ml of the diethyl n-butylmalonate ester was adventitious to the reredisconnection via the missing funnel and the conformation excitered for 5mins, the retaining ester was then adventitious at a flying dropwise rate.When adduction was finished, the conformation was overflowed on a heating bubble for 45 minutes, and then poured into 90mL of dispassioned impart. The conformation was then cooled on ice and NaCl was adventitious until the conformation became saturated. * Contrive of n-Butyl malonic piercing 6M HCl was adventitious to the resulting conformation of potassium n-butylmalonate and the conformation was tested frequently using Congo Red Nursing essay until the pH was short than 1. Behind an pulchritudinous lamina contriveed, the impart lamina of the conformation was gathered indelicate times delay 30mL Et2O. The ether laminas were then fully, dried balance MgSO4 and filtered using starch civilization. Contrive of Caproic Acid: The n-butyl malonic piercing synthesized from the prior lab was poured into a 250mL circular gsmooth flask. Single life of the conformation was carried out. Ether and ethanol respectively were incomplete the principal to be distilled. Finally, decarboxylation was observed, caproic piercing contriveed and was attentive using 50ml circular gsmooth flask and a stopper. Figure 1: Gas Trap Figure 2: Single Life Apparatus Results * Contrive of Diethyl n-butyl malonate: Adduction of diethyl malonate to the yellow NaOEt reredisconnection contriveed a unspotted firm.When EtOH was adventitious to the conformation, the unspotted firm dissolved, and delay the adduction of n-BuBr, the fluent conformation churlish yellow. During overflow thus-far, the conformation modifiable to unspotted. Extraction delay ether disconnected the yellow radical lamina from the evident aqueous lamina. During single life, Et2O distilled principal at ~35oC, followed by EtOH at ~76oC. At ~88oC, merely a very insignificant total of yellow fluent was left in the effervescence flask. The yellow fluent as-well had a disregard piercing trail. The yellow issue was weighed to be 15. 40g: Effervescence flask delay conformation = 143. 61g Flask merely = 128. 1g Product= 143. 61 – 128. 21 = 15. 40g The IR results of the reactants (n-BuBr and diethyl malonate) and the issue (Diethyl n-butyl malonate) are shown under. IR for n-BromoButane Wavelength (cm-1)| Functional Group| Peaks at 2961. 35, 2934. 24 and 2873. 78| Alkyl Csp3 – H| IR for Diethyl malonate Wavelength (cm-1)| Functional Group| Broad peak at 2985. 11| Alkyl Csp3 - H| 2 peaks balancelapped at 1741. 28| Carbonyl Ester| Long peak at 1037. 03| Csp3 - O| IR for Diethyl n-Butylmalonate Wavelength (cm-1)| Functional Group| Long peak at 1733. 86| Carbonyl Ester| Peaks at 2873. 67, 2935. 54, 2960. 6| Alkyl Csp3 - H| * Contrive of Potassium n-Butylmalonate and n-Butyl malonic piercing Conformation of 29. 99g of KOH and ~30mL of H2O executed a evident hot conformation. Adduction of the KOH and H2O conformation to the yellow fluent synthesized aloft resulted in no tint fluctuate. During overflow, no fluctuate was observed on the overflowing conformation; thus-far, a truly piercing trail could be smelled. Adduction of NaCl to the conformation behind resflux, executed no apparent fluctuates either. Adduction of extravagance 6M HCl contriveed an pulchritudinous yellow lamina and when the conformation was tested delay Congo Red Nursing essay, the Nursing essay churlish subterranean bluish.The conformation was gathered indelicate times delay ether and the capacity of the fully ether laminas was approximately 120mL. Adduction of MgSO4 showed no apparent fluctuate. * Contrive of Caproic Acid: IR for Caproic Piercing Wavelength (cm-1)| Functional Group| Peak at 3293. 07| O-H of carboxylic junction| Peak at 2959. 66| Alkyl Csp3 - H| Peak at 1710. 14| Carbonyl Caboxylic piercings| NMR for Caproic Piercing Chemical Shift (ppm)| Functional Group| 0. 902| | | | | | Discussion References Reagent consultation http://www. chemblink. com/products/133-08-4. htm