Method for preparing 2-propylbenzimidazole
A technology of propylbenzimidazole and o-phenylenediamine, which is applied in the direction of organic chemistry, can solve the problems of incomplete reaction of raw materials, inconvenient operation, and inability to directly recycle polyphosphoric acid, etc., so as to facilitate industrial production and operation The process is simple and easy, the effect of saving and controlling production costs
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0027] 700.0 g (6.47 mol) of o-phenylenediamine and 889.0 ml (10.09 mol) of n-butyric acid were stirred evenly, and heated to reflux (at a temperature of 110° C.) for 0.5 hours to react. Part of the reaction liquid was distilled off until the temperature rose to 180°C, and the reaction was continued for 0.5 hours. Cool to 90°C. Pour it into 3.9L aqueous solution of 85 grams of sodium hydroxide, cool to room temperature and stir for crystallization for 1 hour. After filtering, washing with water and drying, 1023.4 g of light red 2-propylbenzimidazole was obtained, the yield was 98%, and the HPLC purity was 99.35%. Recrystallized from ethyl acetate (1:5g:ml) to obtain 956.9 g of off-white solid 2-propylbenzimidazole with a yield of 92% and a HPLC purity of 99.86%. mp159-160°C (melting point was measured with a capillary melting point apparatus, document J.Amer.Chem.Soc., 1937, 59:178-179 reported: mp157.0-157.5°C).
[0028] MS (Q-TOF micro, ESI+ ): 161.1[M+1] + .
[0029] ...
Embodiment 2
[0032] Stir 700.0 g of o-phenylenediamine and 1185.3 ml of n-butyric acid evenly, and heat to reflux for 6 hours. Evaporate 100ml of aqueous n-butyric acid, then add 100ml of n-butyric acid, repeat 5 times. Then the reaction solution was distilled off until the temperature rose to 150° C., and the reaction was continued for 2 hours. The reaction liquid was directly poured into 3.9 L aqueous solution of 85 g of sodium hydroxide, cooled to room temperature and stirred for crystallization for 1 hour. Filtrate, wash with water, and dry to obtain 1027 g of light red 2-propylbenzimidazole with an HPLC purity of 99.12% and a yield of 99%.
Embodiment 3
[0034] 700.0 g (6.47 mol) of o-phenylenediamine and 889.0 ml (10.09 mol) of n-butyric acid were evenly stirred, and heated to reflux for 2 hours. Evaporate 200ml of aqueous n-butyric acid, add sodium chloride to the aqueous n-butyric acid until saturated, then separate the layers, add the n-butyric acid layer to the reaction solution, and heat to reflux for 2 hours. Then the reaction solution was distilled off until the temperature rose to 180° C., and the reaction was continued for 2 hours. The reaction liquid was directly poured into 3.9 L aqueous solution of 85 g of sodium hydroxide, cooled to room temperature and stirred for crystallization for 1 hour. Filtrate, wash with water, and dry to obtain 1030 g of light red 2-propylbenzimidazole with an HPLC purity of 99.45% and a yield of 99%.
PUM
| Property | Measurement | Unit |
|---|---|---|
| boiling point | aaaaa | aaaaa |
| purity | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More