反応 #64363

反応方程式

sulfuric acid

4-cyano-2,2-dimethyl-6-nitro-2H-1-benzopyran

acetic acid

sulfuric acid

→

2,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxylic acid

溶媒

water

反応条件

後処理

1. 1
   温度was heated
2. 2
   温度at reflux for 1.5 hours
3. 3
   洗浄The thus precipitated crystal was washed with water
4. 4
   その他dried
5. 5
   その他recrystallized from a mixed solvent of acetonitrile and water

実験手順

MS: 230 (M+) ##STR41## A mixture of 13.0 g of 4-cyano-2,2-dimethyl-6-nitro-2H-1-benzopyran, 400 ml of acetic acid, 200 ml of water, and 100 ml of concentrated sulfuric acid was heated at reflux for 1.5 hours. After adding 100 ml of concentrated sulfuric acid, the refluxing was further continued for an additional period of 1 hour. The reaction mixture was poured into ice-water. The thus precipitated crystal was washed with water, dried, and recrystallized from a mixed solvent of acetonitrile and water to obtain 11.9 g of 2,2-dimethyl-6-nitro-2H-1-benzopyran-4-carboxylic acid represented by formula shown below.

出典