SU763320A1

SU763320A1 - Method of preparing alpha-chloromethacrylic acid

Info

Publication number: SU763320A1
Application number: SU772498916A
Authority: SU
Inventors: Эльдар Мир Самед Оглы Мовсумзаде; Мамед Гюльмамед Оглы Мамедов; Гусейн Мамед Ага Оглы Мамедов
Original assignee: Азербайджанский институт нефти и химии им. М.Азизбекова
Priority date: 1977-06-24
Filing date: 1977-06-24
Publication date: 1980-09-15

Description

Изобретение относится к способу получения а -хлорметакриловой кислоты, которая находит применение для получения полимеров, а также может быть использована в различных реакциях органического синтеза.The invention relates to a method for producing α-chloromethacrylic acid, which is used to obtain polymers, and can also be used in various organic synthesis reactions.

Известен способ получения а -хлорметакриловой кислоты хлорированием метакриловой кислоты в газовой фазе при 180-190°С в присутствии перлита в качестве катализатора (1).A known method of producing α-chloromethacrylic acid by chlorination of methacrylic acid in the gas phase at 180-190 ° C in the presence of perlite as a catalyst (1).

Недостатком данного способа является то, что он может приводить к получению целевого продукта, загрязненного в основном 2,3-дихлорпропионовой кислотой, что сказывается на выходе целевого продукта. Выход о: -хлорметакриловой , кислоты невелик (82,3%). К недостаткам даиного способа следует отнести также повышенный температурный режим проведения процесса.The disadvantage of this method is that it can lead to the desired product, contaminated mainly with 2,3-dichloropropionic acid, which affects the yield of the target product. The yield of: -chloromethacrylic acid is small (82.3%). The disadvantages of this method should also include increased temperature conditions of the process.

Цель изобретения - повышение выхода целевого продукта и упрощение процесса.The purpose of the invention is to increase the yield of the target product and simplify the process.

Поставленная цель достигается способом получения а -хлорметакриловои кислоты, отличительной особенностью которого является то, что а -хлорметакрилонитрил подвергают гидратации при 85-150°С в присутствии серной кислоты, обычно процесс ведут , в присутствии ингибитора полимеризации при 1.10-115° С.This goal is achieved by the method of producing α-chloromethacrylic acid, the distinguishing feature of which is that α-chloromethacrylonitrile is hydrated at 85-150 ° C in the presence of sulfuric acid, usually the process is carried out in the presence of a polymerization inhibitor at 1.10-115 ° C.

Пример 1. К 0,5 моль (50,75 г) а-хлорметилакрилонитрила при комнатной температуре при перемешивании по каплям добавляют 0/31 г гидрохинона в 100 мл холодной воды и при комнатной температуре порциями добавляют 0,5 моль (48 г) 75% H₂SO₄. Реакционную смесь нагревают 1,20 ч при 85-90° С, после чего к смеси добавляют 65 г (NH$₄)₂CO₃ и перемешивают еще 40 мин, затем фильтруют от (NH₄)₂SO₄, далее экстрагируют эфиром и после удаления эфира остаток перегоняют в вакууме, при этом рыделяется α-хлорметакриловая кислота с выходом 76% (45,79 г).Example 1. To 0.5 mol (50.75 g) of a-chloromethylacrylonitrile at room temperature, 0/31 g of hydroquinone in 100 ml of cold water are added dropwise with stirring, and 0.5 mol (48 g) is added in portions at room temperature 75 % H ₂ SO ₄ . The reaction mixture is heated for 1.20 hours at 85-90 ° C, after which 65 g (NH $ ₄ ) ₂ CO ₃ are added to the mixture and stirred for another 40 minutes, then filtered from (NH ₄ ) ₂ SO ₄ , then extracted with ether and after removal of the ether, the residue was distilled in vacuo, while α-chloromethacrylic acid was recovered in 76% yield (45.79 g).

Пример2. В условиях примера 1 гидратацию проводят при ПО-115° С. Выход составляет 98,5% (59,49 г).Example 2. In the conditions of example 1, hydration is carried out at PO-115 ° C. The yield is 98.5% (59.49 g).

Пример З.В условиях примера 1 гидратацию проводят при 145-15О°С. Выход составляет 81,5% (49,1 г).Example H. Under the conditions of example 1, hydration is carried out at 145-15 ° C. The yield is 81.5% (49.1 g).

Claims

The invention relates to a process for the production of a-chloromethacrylic acid, which is used for the preparation of polymers, and can also be used in various reactions of organic synthesis. A known method for producing a-chloromethacrylic acid by chlorination of methacrylic acid in the gas phase at 180-190 ° C in the presence of perlite as a catalyst {1. The disadvantage of this method is that it can lead to the production of the target product, which is mainly contaminated with 2hzd | chloropropionic acid, which affects the yield of the irradiated product. The yield of α-chloromethacrylic acid is small (82.3%). The disadvantages of this method include the increased temperature regime of the process. The purpose of the invention is to increase the yield of the target product and the simpler process. This goal is achieved by the method of obtaining cc-chloromethacrylic acid, the distinguishing feature of which is that Of-chloromethacrylonitrile is subjected to hydration at 85-150 ° C in the presence of sulfuric acid, usually the process is carried out in the presence of a polymerization inhibitor at 110-115 ° C. 1. To 0.5 mol (50.75 g) of a-chloromethylacrylonitrile at room temperature, stirring is added dropwise to OjOl g of gadrochnon in 100 ml of cold water and 0.5 M (48 g) is added in portions at a constant temperature. 75% H2SO4. The reaction mixture is heated for 1.20 hours at 85-90 ° C, after which 65 g () is added to the mixture and stirred for another 40 minutes, then filtered from (NN4) 7504, then extracted with ether and after removing the ether the residue is distilled in vacuum while cc-chloromethacrylic acid is bored with a yield of 76% (45.79 g). Prtsmer2, Under the conditions of example 1, hydration is carried out at 110-115 ° C. The yield is 98, 5% - (59.49 g). Example Z. Under the conditions of Example 1, hydration was carried out at 145-150 ° C. The yield is 81.5% (49.1 g). Claim 1. Method of preparation (H. Chlormethacrylic acid, characterized in that

3 7633204

in order to increase the yield of the target product 115 C in the presence of polymerization and a process simplification, or-chloromethacrylonitrile.

Lodvergan hydration at a temperature of 85 - Information sources,

150 C in the presence of sulfuric acid. Given in the examination

2. The method according to p. I, different s 1- USSR Copyright Certificate No. 544650,

IBM, that the process is conducted at a temperature of PO-cl. C 07 C-57/06, 1974 (prototype).