Mitsubishi Gas Chemical Company, Inc.

Hirofumi Higuchi

Takafumi Abe

Shuji Ebata

Koichi Kida

Yoshikazu Shima

Hiroyuki Hirayama

Takako Uchiyama

Mariko Abe

Nobuyuki Muro

Kazuto Ikemoto

Hideo Ikarashi

Toshio Kondo

Kazuhiro Sugamura

Jiro Ishikawa

Taiji Matsuzaki

Akitomo Uda

Yoshiyuki Nishide

Toshiyuki Gotoh

A process for preparing a lactate which includes: (a) preparing lactonitrile from prussic acid and acetaldehyde, (b) hydrating the lactonitrile to form lactamide, (c) forming the desired lactate and formamide from lactamide and formate (or methanol and carbon monoxide), (d) separating and collecting components, having a lower boiling point than that of lactate from the reaction liquid in step (c), by distillation under specified conditions, and (e) dehydrating formamide from step (d) to form prussic acid and recycling the prussic acid to step (a). Heretofore, lactates had been manufactured by forming lactonitrile (cyanohydrin) from acetaldehyde and prussic acid, and then esterifying lactonitrile with a mineral acid or the like. However, in this conventional process, ammonium salts were formed as by-products in an amount equal to that of the lactate. According to the present invention, a lactate can be efficiently manufactured on a commercial scale without forming a large amount of the ammonium salts as by-products. In particular, the yield of the lactate can be increased by controlling the formation of 2-formyloxy propionate and also a dimer of a lactate.

Process for preparing lactate

A process for preparing a carboxylic acid ester which includes subjecting a carboxylic acid and an alcohol or a phenol to an esterification reaction in the presence of a silica-titania catalyst. The silica-titania catalyst is prepared by adding an acidic solution containing a silicon compound and a titanium compound dissolved therein to a solution of a basic compound to bring about co-precipitation, in which the acidic solution is a nitric acid-acidic solution or a sulfuric acid-acidic solution, a ratio of the amount (gram equivalent) of nitric acid or sulfuric acid to the amount (mol) of the silicon compound in the acidic solution is 0.5 to 50 and the amount of the titanium compound in the acidic solution is such that a ratio of titania (TiO.sub.2) in the silica-titania catalyst is 1 to 50% by weight.

Process for preparing a carboxylic acid ester

A process for preparing a silica-titania catalyst by adding an acidic solution containing a silicon compound such as sodium silicate and a titanium compound such as titanium sulfate dissolved therein to a solution of a compound such as ammonium bicarbonate to bring about co-precipitation, in which the acidic solution is a highly concentrated nitric acid-acidic or sulfuric acid-acidic solution, and a ratio of the dissolved titanium compound in the acidic solution is regulated in a certain range. According to this process, a catalyst capable of exerting a high performance in an esterification reaction and the like can be efficiently obtained.

Process for preparing silica-titania catalyst

There is disclosed a process for producing .alpha.-hydroxyisobutyramide by hydration reaction of acetone cyanohydrin in the presence of a catalyst consisting essentially of manganese dioxide which process comprises pretreating the catalyst with a reducing agent. The above process is capable of eliminating the catalyst clogging trouble due to the deposition of the by-produced oxamide and thus proceeding with long-term reaction with the stabilized catalyst performance.

Process for producing .alpha.-hydroxyisobutyramide

There is disclosed a process for efficiently producing hydrogen cyanide at a reaction temperature of preferably 250.degree. to 550.degree. C. by a catalytic dehydrative reaction of formamide which comprises employing as a catalyst, a manganese oxide (MnO) and/or a magnesium oxide (MgO) each modified with an alkali metal (Na, K, Rb, Cs, etc. ). The above process is capable of producing hydrogen cyanide at an enhanced conversion efficiency of formamide and at a high selectivity while minimizing the by-production of ammonia. The use of the catalyst comprising as a principal component, MnO modified with an alkali metal is particularly effective in prolonging its service life and enables a long-term stable operation.

Process for producing hydrogen cyanide

There is disclosed a process for efficiently producing methyl .alpha.-hydroxyisobutyrate from .alpha.-hydroxyisobutyramide and methyl formate by means of reaction distillation which comprises feeding .alpha.-hydroxyisobutyramide and an alkali metal hydroxide in a continuous distillation column to prepare therein the dehydrated condensate of .alpha.-hydroxyisobutyramide with the alkali metal hydroxide as the catalyst and reacting remaining .alpha.-hydroxyisobutyramide with methyl formate in the presence of the dehydrated condensate as the catalyst. According to the above process, the objective methyl .alpha.-hydroxyisobutyrate is continuously obtained in high yield and high selectivity without any operational trouble.

Process for producing methyl .alpha.-hydroxyisobutyrate

There is disclosed a process for producing methyl methacrylate through gas-phase catalytic reaction of methyl .alpha.-hydroxyisobutyrate which comprises feeding methanol in an amount by weight of 0.1 to 3.0 times the methyl .alpha.-hydroxyisobutyrate in a reactor along therewith and proceeding with the reaction at a reaction temperature in the range of 230.degree. to 300.degree. C. by the use of a transition-type synthetic faujasite zeolite having a specific lattice constant and a specific Na content (Na/Al) as the catalyst. The process is capable of stably producing the objective product having excellent quality in high yield for a long period of time while preventing the problems of early deterioration of the catalyst and coloring of reaction product.

Process for producing methyl methacrylate

There is disclosed a process for efficiently producing a carboxylic acid ester and formamide by reacting a carboxylic acid amide with a formic acid ester or with an alcohol and carbon monoxide in the presence of a strongly basic anion-exchange resin. By the use of the strongly basic anion-exchange resin as the catalyst, the process of the present invention enables the efficient production of the carboxylic acid ester as well as formamide from the Carboxylic acid amide and Formic acid ester, etc. with a high selectivity under mild reaction conditions and facilitates the separation of the catalyst from the reaction product, thereby greatly enhancing the industrial significance of itself.

Process for production of carboxylic acid ester and formamide

A process for producing methacrylic acid which comprises: (I) producing acetonecyanohydrin from prussic acid and acetone; (II) hydrating the acetonecyanohydrin obtained in step (I) to form .alpha.-hydroxyisobutyric acid amide; (III) reacting the .alpha.-hydroxyisobutyric acid amide obtained in step (II) with methyl formate or with methanol and carbon monoxide to form methyl .alpha.-hydroxyisobutyrate and formamide; (IV) hydrolyzing the methyl .alpha.-hydroxyisobutyrate obtained in step (III) to form .alpha.-hydroxyisobutyric acid; (V) dehydrating the .alpha.-hydroxyisobutyric acid obtained in step (IV) to form methacrylic acid; and (VI) dehydrating the formamide separated from the products obtained in step (III) to form prussic acid and recycling the prussic acid to step (I) as a starting material. The process is capable of producing methacrylic acid from readily available starting materials with a high yield and selectivity, without forming undesirable by-product or waste materials, such as ammonium sulfate.

Process for producing methacrylic acid

Carboxylic acid esters and formamide are efficiently obtained by reacting carboxylic acid amides and formic acid esters, or by reacting carboxylic acid amides, alcohols and carbon monoxide in the presence of a dehydrated condensate of carboxylic acid amide with an alkali metal hydroxide or an alkaline earth metal hydroxide catalyst.

Process for production of carboxylic acid esters and formamide

A process for preparing an amide by hydrating a cyanohydrin with a denatured manganese dioxide catalyst. The catalyst is prepared by reacting an aqueous permanganate solution and an aqueous manganese (II) compound solution in an acidic aqueous solution at a temperature of 70.degree. C. to 150.degree. C.

Process for producing a denaturated manganese dioxide catalyst for the

A process for producing .alpha.-hydroisobutyric acid amide by a hydration reaction of acetonecyanohydrin in the presence of a catalyst containing manganese dioxide as a main component, and also in the presence of an oxidizing agent. In accordance with the process, the service life of the catalyst is increased, and the .alpha.-hydroxyisobutyric acid amide is produced in a high yield.

Process for producing alpha-hydroxyisobutyric acid amide

Disclosed is a process for producing methyl methacrylate which comprises:

A process for producing .alpha., .beta.-unsaturated carboxylic acid ester which comprises catalytically reacting .alpha.-hydroxycarboxylic acid ester with crystalline aluminosilicate catalyst, and then catalytic reacting the resulting reaction product with solid acid catalyst. According to the process, .alpha., .beta.-unsaturated carboxylic acid ester of a high purity, and a high quality, without by-product, can be produced efficiently.

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Niigata, Japan

Hirofumi Higuchi