| 摘要 |
PROBLEM TO BE SOLVED: To obtain pyrazo[1,5-a]pyrimidines useful for an oxidizing base in a medium for oxidizing dye of keratin fibers especially human keratin fibers. SOLUTION: The compound is expressed by formula I R1 to R4 are each H, an 1 to 4C alkyl or the like; X is H, sulfonic acid or the like; i is 0 or 1 to 3; p, q and n are each 0 or 1; however p+q≠0 and n is 0 when p+q=2, NR1R2 and NR3R4 are each in position (2, 3), (5, 6) or the like, and n=1 when p+q=1 and NR1R2 (or NR3R4) and OH are each in position (2, 3), (3, 5) or the like, excluding pyrazo[1,5-a]pyrimidine-6,7-diamine}, for example pyrazo[1,5- a]pyrimidine-3,7-diamine. The compound of formula I is manufactured by cyclizing, for example, 4-nitro-2H-pyrazol-3-ylamine hydrochloride in the presence of derivatives of acrylonitrile of formula III to afford the compound of formula IV and reducing the compound to obtain the compound of formula V.
|
