SU122145A1 - The method of obtaining nitrospirt - Google Patents

Description

The known reaction of obtaining nitroalcohol by the interaction of nitroparaffins with ketones or higher aldehydes in the presence of bases B as catalysts is extremely slow. The use of ultrasound is known to accelerate this type of reaction and increase the yield for the case of 1-nitromethylcyclohexanol-1.

Further, the authors showed the effectiveness of ultrasound on the reaction with other nitroparaffins, ketones and aldehydes. In accordance with this, it has been proposed, when preparing other nitrosprites from nitroparaffins and aldehydes or ketones, in the presence of base catalysts, to influence the reagent mixture with ultrasound. This makes it possible to significantly shorten the reaction time while simultaneously increasing the yield of nitro-alcohol.

Example 1. In a flat-bottomed flask, 61 g of nitromethane, 265 ml of absolute acetone and sodium methylate prepared from 0.85 g of sodium and 35 ml of absolute methanol are mixed. The flask is mounted directly on an ultrasonic emitter with a frequency of 21.3 kHz. The reaction is carried out at 20 °, cooling the flask with water. After two hours of sonication, the mixture is neutralized with 10N hydrochloric acid, filtered to separate the sodium chloride, and the filtrate is subjected to fractional distillation. The result is 1-nitro-2-methyl-2-propanol with a yield of 51 / about theoretical per nitromethane, t. Kip. (12 mm). With simple mixing of this mixture for 30 hours. the nitro alcohol yield is 30Vo.

Example 2. A mixture of 45 g of 2-nitropropane, 145 g of cyclohexapone and sodium methylate, prepared from 0.5 g of sodium and 30 ml of methanol, is exposed to ultrasound for 2 hours. The mixture is then neutralized with 10 N hydrochloric acid and the aqueous layer is separated. The organic layer is subjected to fractional distillation in vacuo. After the separation of the unrelated initial materials, obtain No. 122145

105 (11% of the theoretical amount in the calculation of nitrite) 1- (B-nitroisopropyl) -1-cyclohexanol, t.kip. 131-1 (1b mm) With simple stirring of such a mixture for 20 hours. the yield of nitrosling is 8%. Poor 3 K mixture of 61 g of nitromethane and 1 g of calcium hydroxide is poured over 1 hour at 20-25 152 g of acetaldehyde dissolved in 75 ml of water. After sonication for 25 hours, the reaction mass is saturated with carbon dioxide. The precipitated calcium carbonate is filtered off and the filtrate is subjected to fractional distillation in vacuo. After distillation of the unreacted reagents, a brown mass of 3-nitro-2,4-pentanediol remains in the flask. 65-67 mixed with a small amount of 1-nitro-2-propanol. The yield of the product is 83 theoretical with respect to nitromethane.

Without sonication, the SQo / o yield is achieved after holding at 20-25 ° for 40 hours.

Subject invention

A method of producing nitroalcohols from nitroparaffins and aldehydes or ketones in the presence of bases, characterized in that, in order to accelerate the reaction and increase the yield, the mixture of reagents is subjected to the action of ultrasound.