Studies of Heterocyclic Compouds. XII. Structures of Acetylated Products of 5-Hydroxy-4-(2-hydroxyethyl)-3-methylpyrazole

• Published in: Bulletin of the Chemical Society of Japan Vol. 50; no. 11; pp. 2991 - 2994
• Main Authors: Ochi, Hisao, Miyasaka, Tadashi, Arakawa, Kiichi
• Format: Journal Article
• Language: English
• Published: Tokyo The Chemical Society of Japan 01.11.1977; Chemical Society of Japan
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.50.2991

Acetylation of 5-hydroxy-4-(2-hydroxyethyl)-3-methylpyrazole (1) produced five acetyl derivatives: 4-(2-acetoxyethyl)-5-hydroxy-3-methylpyrazole (2), 4-(2-acetoxyethyl)-2-acetyl-5-hydroxy-3-methylpyrazole (3), 4-(2-acetoxyethyl)-1-acetyl-5-hydroxy-3-methylpyrazole (4), 5-acetoxy-4-(2-acetoxyethyl)-2-acetyl-3-methylpyrazole (5), and 1-acetyl-5-hydroxy-4-(2-hydroxyethyl)-3-methylpyrazole (6). The partial hydrolysis of 3 and 5 in aq acetic acid gave the monoacetate (2). The triacetate (5) afforded 3 by heating in a mixture of pyridine and meththanol. Migration of the acetyl group from the N1-position to the C5-O- and to the side chain-O-position is suggested. It is also suggested that the triacetate (5) may be effective for acetylation of amines.