反应详情

To a stirred and cooled mixture of 43.7 parts of 3-amino-4-(butylamino)benzoic acid and 200 parts of a hydrochloric acid solutin 6N was added dropwise a solution of 22 parts of sodium nitrite in a small amount of water. Upon complete addition, the reaction mixture was stirred for 4 hours at 10°-20° C. The product was filtered off, washed with 30 parts of water and crystallized from a mixture of 2-propanone and ethyl acetate. The product was filtered off and dried, yielding 33.3 parts (72.6%) of 1-butyl-1H-benzotriazole-5-carboxylic acid; mp. 192.5° C. (int. 9).

1. temperaturecooled
2. additionUpon complete addition
3. stirringthe reaction mixture was stirred for 4 hours at 10°-20° C
4. filtrationThe product was filtered off
5. washwashed with 30 parts of water
6. customcrystallized from a mixture of 2-propanone and ethyl acetate
7. filtrationThe product was filtered off
8. customdried