In this lab, caproic acid solution was synthesized in a multi-step process that involved the synthesis of three intermediates – diethyl n-butylmalonate, potassium n-butylmalonate, and n-butyl malonic acid correspondingly. An IRGI was used to characterize the starting materials, n-bromobutane, plus the first more advanced, diethyl n-butylmalonate, while IR and NMR were utilized to characterize the last product, caproic acid. Reactions, Mechanism and Theory Caproic acid a.
k. a n-hexanoic acidity is a carboxylic acid created from hexane that has the general method C5H11COOH. It is just a colorless greasy liquid using a really pungent odor associated with goats.
Caproic chemical p was produced in a multi-step process which produced three intermediates , diethyl n-butylmalonate, potassium n-butylmalonate, and n-butyl maonic chemical p. The activity of caproic acid engaged alkylation, saponification, and decarboxylation reactions. The first more advanced, diethyl n-butylmalonate – a diethyl ester of malonic acid – was synthesized via an alkylation reaction. Alkylation reactions involve the formation and alkylation of an enolate. In this research laboratory, NaOEt, a strong base was used to pull away one of the most acid? hydrogens in the carbonyl ester – diethylmalonate – to form an enolate. In order to alkylate the alpha dog position which now has a negative charge, the enolate was used to harm an alkyl halide, 1-bromobutane via Sn2 mechanism. The mechanism intended for the above response is shown below: The other intermediate, potassium n-butylmalonate, was synthesized by saponification from the first intermediate, diethyl n-butylmalonate, with potassium hydroxide.
The hydrolysis of diethyl n-butylmalonate led to the formation of potassium n-butyl malonic chemical p by shedding the ethoxy group (-OCH2CH3) from both equally sides of the carbonyl ester. Further deprotonation in the formed acid by -OCH2CH3 forms a carboxylate, potassium n-butylmalonate. The mechanism to get the above process is shown below: N-butyl malonic chemical p, the third more advanced, was right away synthesized through the potassium n-butylmalonate by the protonation of potassium n-butylmalonate with the addition of excess HCl as shown below: The last step of this research laboratory involved the decarboxylation of n-butyl malonic acid to form caproic chemical p. Decarboxylation is definitely the removal of a carboxyl group, -COOH, via a carbonyl compound to create CO2 and an enol which further more tautomerizes to form a ketone. Through this lab, removing a -COOH from the n-butyl malonic acid formed 1, 1-dihydroxy-hex-1-ene. Tautomerization of this item leads to the organization of caprioc acid. the above mentioned reaction system is displayed below: Reagent Tables Stand 1: Activity of diethyl n-butylmalonate (Reagents and Product) Name| Substance Formula| Molecular Weight| Density(g/ml)| Conc(M)| Amount(g or ml)| Amount(moles)| Burning Point(0C)| Hot Point(0C)| Salt Ethoxide| NaOEt| 68.
05| 0. 868| | 50ml9. 1187g|. 134| 260| , | Diethyl malonate| | one hundred sixty. 17| 1 . 055| | 20. 34ml21.
46g|. 134| -50| 199| 1-Bromobutane| n-BuBr| 137. 2| 1 . 270| | 14. 5ml18. 36g|. 134| 1 .
2686| tips. 4| Overall Ethanol| EtOH| 46. 07| 0. 789| | 35ml| | -114. 3| 80. 4| Ether| Et2O| seventy four. 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| Desk 2: Activity 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)| Burning Point(0C)| Cooking food 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| | | | | | | | | Table several: Synthesis of n-Butyl malonic Acid (Reagents and Product) Name| Substance Formula| Molecular Weight(g/mol)| Density(g/ml)| Conc(M)| Amount(g or ml)| Amount(moles)| Melting Point(0C)| Hot Point(0C)| Potassium n-butylmalonate| | | | | | | | | Hydrochloric acid| HCl| 36. 46| 1 . 180| | | | -27. | 110| Ether| Et2O| 74. 12| 0. 7134| | | | -116. 3| thirty four.
6| Magnesium Sulfate| MgSO4| one hundred twenty. 42| 2 . 66| | | | 1124| , -| n-Butyl malonic acid| C7H12O4| | | | | | | | Table some: Synthesis of Caproic Acid (Reagents and Product) Name| Chemical Formula| Molecular Weight(g/mol)| Density(g/ml)| Conc(M)| Amount (g or ml)| Amount (moles)| Melting Level (0C)| Hot point(0C)| n-Butyl Malonic Acid| C7H12O4| one hundred sixty. 17| , -| | | | 102-105| , | Caproic Acid| C6H12O2| 116. 16| 0. 920| | | | -3| 202-203|Procedure: 2. Synthesis of Diethyl n-butylmalonate (IV) 0mL of NaOEt and a magnetic mixing bar had been added to a dry 250mL round bottom flask fitted with a fondre, a calcium chloride blow drying tube, and a separatory funnel that has been attached to the set-up by using a Claisen joindre. 20.
34mL of diethyl malonate was added to the solution with the separatory channel over a period of about fifteen minutes. Next, 35mL of EtOH and 14. 5mL of n-BuBr were included with the blend respectively. The answer was refluxed for a couple of minutes using a heat mantle then cooled on ice. These mixture was later added into 200ml of drinking water and then transferred to a 500mL separatory funnel. 0mL of ether was used to remove the combination first and then 20mL of ether each was used to extract the aqueous level four more times. The organic layers were after that combined and dried with MgSO4.
The blend was strained and then evaporated to ~100mL. The final answer was then simply transferred to a 250mL round bottom flask and simple work was completed. After azure and ethanol had unadulterated off, the diethyl n-butylmalonate was collected. When the work temperature come to ~90, the method was stopped and the produced diethyl n-butylmalonate was kept in the round bottom flask. An MARCHAR of the starting materials, diethyl malonate and n-BuBr, plus the product diethyl n-butylmalonate were run. 2. Synthesis of potassium n-butylmalonate The diethyl n-butylmalonate was transferred to a tiny separatory channel and a condenser, mix bar, Claisen adapter plus the separatory flask was mounted on the 250mL distillation flask. A solution of 30g KOH in 30mL of drinking water was well prepared and this option was put into the work flask.
~5ml in the diethyl n-butylmalonate ester was added to the solution via the shedding funnel as well as the mixture stirred for 5mins, the remaining ester was in that case added in a rapid dropwise rate. When ever addition was complete, the mixture was refluxed on the heating mantle for forty five minutes, and then put into 90mL of cold water. The mixture was then cooled down on ice and NaCl was added until the mix became saturated. * Synthesis of n-Butyl malonic acidity 6M HCl was included with the causing mixture of potassium n-butylmalonate plus the mixture was tested often using Congo Red daily news until the ph level was lower than 1 . Following an oily layer shaped, the water coating of the blend was removed four instances with 30mL Et2O. The ether layers were after that combined, dried over MgSO4 and filtered using gravity filtration. Synthesis of Caproic Acid: The n-butyl malonic acid synthesized from the previous lab was poured in a 250mL rounded bottom flask.
Basic distillation of the mixture was carried out. Azure and ethanol respectively had been among the first to become distilled. Finally, decarboxylation was observed, caproic acid formed and was collected applying 50ml round bottom flask and a stopper. Number 1: Gas Trap Determine 2: Simple Distillation Equipment Results * Synthesis of Diethyl n-butyl malonate: Addition of diethyl malonate towards the yellow NaOEt solution shaped a white-colored solid. Once EtOH was added to the mixture, the white stable dissolved, device addition of n-BuBr, the liquid mix turned yellow. During reflux however , the mixture changed to white. Removal with azure separated the yellow organic and natural layer from your clear aqueous layer.
During basic distillation, Et2O distilled first at ~35oC, followed by EtOH at ~76oC. At ~88oC, only a very small amount of yellow liquid was left in the boiling flask. The yellow liquid as well had a minor pungent stench. The yellow product was weighed to be 15. 40g: Boiling flask with combination = 143. 61g Flask only = 128. 1g Product= 143.
61 – 128. 21 = 15. 40g The VENTOSEAR results from the reactants (n-BuBr and diethyl malonate) and the product (Diethyl n-butyl malonate) are proven below. IRGI for n-BromoButane Wavelength (cm-1)| Functional Group| Peaks in 2961. thirty-five, 2934. twenty four and 2873. 78| Alkyl Csp3 – H| VENTOSEAR for Diethyl malonate Wavelength (cm-1)| Practical Group| Wide-ranging peak in 2985.
11| Alkyl Csp3 , H| two peaks overlapped at 1741. 28| Carbonyl Ester| Extended peak in 1037. 03| Csp3 , O| IR for Diethyl n-Butylmalonate Wavelength (cm-1)| Useful Group| Lengthy peak in 1733. 86| Carbonyl Ester| Peaks by 2873. 67, 2935. 54, 2960. 6| Alkyl Csp3 , H| * Activity of Potassium n-Butylmalonate and n-Butyl malonic acid Blend of 29.
99g of KOH and ~30mL of H2O developed a clear popular mixture. Addition of the KOH and INGESTING WATER mixture to the yellow the liquid synthesized over resulted in no color modify. During reflux, no transform was noticed on the refluxing mixture, however , a really stinky odor could possibly be smelled. Addition of NaCl to the mixture after resflux, produced zero observable changes either. Addition of surplus 6M HCl formed an oily yellow-colored layer and when the mix was examined with Congo Red paper, the newspaper turned profound blue. The mixture was extracted four times with ether as well as the volume of the combined azure layers was approximately 120mL. Addition of MgSO4 revealed no visible change.
* Synthesis of Caproic Acid: IRGI for Caproic Acid Wavelength (cm-1)| Functional Group| Peak at 3293. 07| O-H of carboxylic compound| Optimum at 2959. 66| Alkyl Csp3 , H| Peak at 1710. 14| Carbonyl Caboxylic acids| NMR for Caproic Acid Chemical Switch (ppm)| Functional Group| 0. 902| | | | | | Discussion Sources Reagent desk http://www. chemblink. com/products/133-08-4.