CS258706B1

CS258706B1 - Method of aliphatic carboxylic acids' benzyl esters production with carbon numbers 2 till 6

Info

Publication number: CS258706B1
Application number: CS859006A
Authority: CS
Inventors: Dusan Mravec; Milina Cihova; Jan Vojtko; Jan Ilavsky
Original assignee: Dusan Mravec; Milina Cihova; Jan Vojtko; Jan Ilavsky
Priority date: 1985-12-09
Filing date: 1985-12-09
Publication date: 1988-09-16
Also published as: CS900685A1

Abstract

RiešenSm sa pripravujú benzylové estery alifatických karboxylových kyselin s pečtom uhlíkev 2 až 6 o čistoto až 99,9 % reakciou benzylalkoholu s kyselinou octovou, proplonovou, máslovou, lzcmaslovou, valérovou, Izovalérovou a kaprcnovou za přítomnosti kyslých katalyzátorov ako je kyselina sírová, p-toluénsulfoncvá, katsxy, přírodně a syntetické hllnltokrsmlčitany v H- -forme, kyselina chlorovodíková. Podstatou riešenia je, že esterlflkácla sa uskutočftuje za přítomnosti organického uhlovodíkového rozpúšfadta, ako je n-heptán, n-hexán, cyklchexán, xyleny alebo benzén v množstve 10 až 50 % hmot. za súčasného oddestilovania reakčnej vody a nadbytku jednej reakčnej zložky, pričom před lzoiáclou esteru z reakčnej zmesí sa odstráni uhlovodíkové rozpúšíadlo a nezreagovaná karboxylové kyselina alebo benzylalkohol destlláciou za znlženého tlaku 0,13 až 13 kPa.Benzyl esters are prepared by resolution aliphatic carboxylic acids with a liver carbon 2 to 6 by a purely 99.9% reaction benzyl alcohol with acetic acid, proplonic, buttery, lzcbutyl, valeric, Isovaler and caprine in the presence acid catalysts such as acid sulfuric, p-toluenesulfonate, katsxy, naturally and synthetic hypersulphates in H- -forme, hydrochloric acid. The essence The solution is that esterlflaks are carried out in the presence of an organic hydrocarbon a solvent such as n-heptane, n-hexane, cyclchexane, xylenes or benzene in amounts 10 to 50 wt. while distilling off reaction water and excess one reaction % of the component, wherein the z-ester is from of the reaction mixture, the hydrocarbon solvent is removed and unreacted carboxylic acid or benzyl alcohol by distillation under reduced pressure pressure of 0.13 to 13 kPa.

Description

CZECHOSLOVAK SOCIALISTIC

REPUBLIC OF I1S)

DESCRIPTION OF THE INVENTION

TO COPYRIGHT CERTIFICATE 258706 (11) (|1 |

(51) Int. Cl? C 07 C 89/033 (22) Registered 09 12 85121) (PV 9006-85) (-10) Published 15 01 88

OAAD FOR INVENTIONS AND DISCOVERIES (45) Published 15 01 89 (75)

Author of the invention MRAVEC DCSAN doc. lng. CSc., ClHOV.A MILINA lng. CSc.,

VOJTKO JAN Lng. CSc., ILAVSK? JAN prof. Lng. DrSc., BRATISLAVA (54) Method of production of benzylic chlorides of aliphatic carboxylic acids by carbon atoms 2 to 8

The solution is to prepare benzyl esteryaliphatic carboxylic acids with carbons having a purity of up to 99.9% of benzyl alcohol with acetic acid, proplonic acid, butyric acid, butyric acid, valeric acid, isovaleric acid and capric acid in the presence of acidic catalysts such as is sulfuric acid, p-toluenesulfonate, katsxy, natural and synthetic hypoclurates in H-form, hydrochloric acid. Most importantly, the ester bleach is carried out in the presence of an organic hydrocarbon solvent such as n-heptane, n-hexane, cyclohexane, xylenes or benzene in an amount of 10 to 50% by weight. with simultaneous distillation of the reaction water and excess of one reactant, by removing the hydrocarbon solvent and unreacted carboxylic acid or benzyl alcohol from the reaction mixture by distillation under reduced pressure of 0.13 to 13 kPa, 25870 »258708

The present invention relates to the production of alkyl esters of polypropoxy acids with a number of 2 and 2 moieties. G. Tleto esterysa used! in function! erom in the foodstuff industry and, for example, benzyl acetate as fragrance [hives in kozinetlckoin.

Benzyl esters of carboxylic acids are generally prepared! by esterifying the corresponding acids with benzyl alcohol in the presence of an acid catalyst. Stage Erdos J., Sa-lnzar Μ. E. Clencls (Mex.) 12, 223-20 (1933), the benzylic esters of carboxylic acids are prepared! esterifying by catalysis with chlorosulfonic acid and using chloroform as an azeotrope additive, in the amounts of 53 to 84 ° C. Stage Joshl DV, Mercliant f. Rt J. Sel. Indian. Research 14 8,482-3 (1959), beuzyl acetate is prepared by benzyl chloride reacting with sodium acetate in an aqueous medium in a volume of 68%.

The benzylic esters of carboxylic acids with the number 2 to 6 are formed by the reaction of benzyl alcohol with acetic acid, propionic acid, butyric acid, valeric acid and capric acid in the presence of acidic catalysts, preferably sulfuric acid. The essential feature of the invention is that the ester is carried out in the presence of an organic hydrocarbon solvent such as n-heptane, n-hexahydrate. cyclohexane, xylenes, or benzates in the amount of 10 to 50 ° C by weight; with simultaneous removal of the water of reaction and thereby shifting the reaction in the formation of estrates, whilst complete conversion of the benzyl alcohol is achieved. or an acid or an ester to an ester. It is necessary to work one-above-one in the production of said esterev; for that reason. that, in the production of benzyl acetyl and benzylproplonate, vasotrope with water and discharger, some of the aforementioned acids which pass into the conduit are discharged. thereby losing the reaction mixture. For acids having a carbon number of 4 to 5, it is necessary to work with the benzyl alcohol overhang to render the acids full, since the smelly smell and do not carry! Do not even get into the esters, which can be used mainly as a taste and fragrance in the food industry. The first three hydrocarbons are preferred for the food industry from low toxicity. In this way, the benzyl esters of benzylpropylate or benzylproplonate are esterified in excess of acetic acid or propionic acid, 1.2 to 1.7 moles of acid per mole of benzyl alcohol or from 1.1 to 1.5 moles of propionic acid on molybenzyl alcohol. In the process for the preparation of carboxylic acid benzyl esters with carbon numbers 4 to 6, esteriflcalae is carried out in excess of benzyl alcohol. from 1.01 to 1.5 moles of benzyl alcohol per mole of cellulose. In the production of benzyl esters at lehoddestllovan! the sulfuric acid is added to the reaction mixture, the latter is sulfonated to the henene nuclei in an additional manner, resulting in an atmospheric reaction of the reaction mixture during the operation under atmospheric pressure, and this may result in an esterification reactor. This is avoided by dissolving the reaction mixture after esterification, with a pressure of 0.13 to 13 kPa and preferably at a pressure of 0.6 to 2 kPa. In this way, it is possible to carry out the esterflection repeating with the sulfuric acid as catalyst without substantial change in the catalytic properties! sulfuric acid] and without the magnesium stearate of the reaction product. An advantage of the process of the invention is that the acid catalyst can be used by the ester and the ester produced from the reaction mixture after removal. the solvent and the component used in excess were distilled under reduced pressure to prevent the ester from being produced. Another advantage of the process according to the invention is that in 1-reel! the ester from the reaction mixture does not appear to be yellow, and the other catalyst may be used in an amount of esters of near the theoretical amount, with the purity of the ester 99.9pre.

The process for the preparation of benzyl esters is moreover described in the non-limiting examples, but is not limited thereto. Example 1

108 g (1 mole) of benzyl-alkane are metered into an ester-reactor of 500 cm @ -1 equipped with a rectification column (P? = 5), a thermometer and an overflow (sulfur-ncm 1 organic phase) of the phase separator. .ol, 73 g (1.3 mole) of acetic acid 1.02 g (0.01 mole) of sulfuric acid] at a concentration of 96% by weight and 50 cm @ -1 of n-heptane. 13 g of reaction water are formed, resulting in complete conversion of the benzyl alcohol to the ester, and the water is azeotroped with n-heptane and acetic acid to give a total of 12 g of water to the aqueous phase. and heptane and a pressure of 1.99 kPa and a residue of unreacted acetic acid and then benzylacetate in an amount of 112.5 g (75% of the amount of ester produced) and a residue, i.e. 37.3 g as sulfuric acid are left in a batch for the next batch within one cycle of batch. EXAMPLE 2 108 g (1 mol) of benzyl alcohol are added to the distillation residue after the preparation of the benzyl acetate in Example 1 above. 78 g (1.3 mol) of acetic acid and 50 cm @ 3 of n-heptane (distilled from the reaction mixture in Example 1). Este-

Claims

238706 PSEbMST EXTRACTION is carried out as in Example 1. This is how to make! 150 with crude benzyl acetate, which is distilled. 142 g of 99.9% pure ester are obtained. EXAMPLE 216 g (2 mole) of benzyl alcohol, 178 g (2.4 mole) of propionic acid, 2.04 g (0.02 mole) of sulfuric acid are metered into a 1 000 cra: 1 ester reactor. ) and 60 cm @ 3 of benzene. Esteriflication is completed after 70 minutes when 36 g of reaction water is distilled off, which is separated in the phase phase as the forward phase and Idopo neutralized into waste. The reaction mixture is then distilled off benzene (propellants) and a pressure of 1.33 kPa (0.001 psi) of reacted proplonic acid and end of the propylpropane (229.9 g, 70% of the ester produced). The distillation residue (98.5 g of ester) as a) sulfuric acid is left in the next batch reactor within one cycle of 5 liters, whereby the activity of the catalyst is unsatisfactory. A benzylpropionate of 99.9 purity was obtained from the ester prepared on a rectifying column with a 6 TP efficiency. Example 4 Preparation of benzyl butyrate was carried out in the same apparatus as described in Example 1. In this case, an excess of benzyl alcohol is formed, which is formed by the butyric acid), and this fifth intermediate line overflows the acid and has a complete zerogelation. not to esterify. 88. ’is charged into the reactor. and (1 mole) of butyric acid), 113.5 g (mi, 0.5 mole of benzyl alcohol, 1.02 g (0.01 mole) of acid and 50 cm @ 3 of n-hentane. in this case, it is only a binary azeotrep.-heptar. water.

CLAIMS 1. Production of benzylic esters of aliphatic carboxylic acids with carbon numbers 2-6 by reacting benzyl alcohol with acetic, proplonic, butyric, butyric, valeric, isovaleric and caproic acid in the presence of acidic catalysts such as sulfuric acid, p-toluenesulfonate - cation exchangers, naturally occurring and synthetic hypochlorite in H-form, hydrochloric acid, characterized in that it is esterified in the presence of an organic hydrogen sulfide solvent such as n-heptane, n-hexane, cyclohexane, xylenes or benzene in an amount of 10 to 50 wt. with distillation of the reaction water and excess of one reaction component, the ester is removed from the reaction mixture by distillation. After the esterification is complete, the heptane is distilled off and the pressure of 1.3 kPa is the remainder of the unreacted benzyl alcohol (1 fraction). and then benzyl butyrate in an amount of 124.7% (70%). The ester residue and catalyst remain in the next batch reactor and, after addition of the same number of layers, is esterified in the same manner. The distilled ester can be read! demanded purity of 99.9% rectangular 1.3k? EXAMPLE 5 1021 g (1 mole) of lzovaleric acid, 109.2 mols of benzyl alcohol (1.01 mole, 1.02 g (0.01 mole) of acid) and 60 cm @ 3 of cyclohexane are charged into the reactor as in Example 1 above. After the end of the ester cycle, the cyclohexane pressure of 2 kPa and the crude benzyl zovalerate in the amount of 125 3 (65 k of the produced amount) are distilled off at atmospheric pressure and 57 g together with the catalyst remain in the reactor for a further batch of one cycle of at least 5 batches. The benzylzovalerate produced is a carbon black preformed (1 fraction representing unreacted benzyl alcohol) and a major fraction of benzylvalerate having a purity of at least 99.8% as determined by gas chromatography Example 6: 103 g are charged into the reactor as in Example 1 (1 mole) of benzyl alcohol, 73 g (1.3 mole) of acetic acid, 1.73 g (0.01 mole) of p-toluenesulfonic acid and 60 cm -1 of 1-heptane The reaction is carried out as in Example 1. and a solvent at atmospheric pressure and a pressure of 2 kPa. acetic acid) and benzyl acetate in an amount of 112.6 g (75% b) of the ester produced. The ester residue and the catalyst are used as feedstock after the addition of the raw materials to the previous esterification. the hydrocarbon solvent and the unreacted carboxylic acid or benzyl alkoxide by distillation under reduced pressure of 0.13 to 13 kPa.

2. The method of clause 1, characterized by sat. that the esterification is carried out in an excess of acetic acid or proplonic acid in an amount of 1.2 to 1.7 moles of acetic acid per mole. benzyl alcohol or 1.1 to 1.3 moles of proplonic acid per mole of benzyl alcohol.

3. A process according to claim 1, wherein the esterification of the carboxylic acids with the number of carbons 4 to 6 is carried out in excess of benzyl alcohol, 1.01 to 1.5 moles of benzyl alcohol per mol of carboxylic acid.