Ethanol → 5-[(Ethoxy-methylene)amino]-1-methyl-1h-pyrazole-4-carboxylic acid, ethyl ester

Reaction equation

[CH3:1][N:2]1[C:6]([NH2:7])=[C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:4]=[N:3]1.[CH:13]([OH:16])(O)O.[CH2:17](O)[CH3:18]>>[CH2:17]([O:16][CH:13]=[N:7][C:6]1[N:2]([CH3:1])[N:3]=[CH:4][C:5]=1[C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH3:18]

Participants

Reactant 3

HCID 702Ethanol

HCID 271299Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate

HCID 5231666Orthoformic acid

Product 1

HCID 867361415-[(Ethoxy-methylene)amino]-1-methyl-1h-pyrazole-4-carboxylic acid, ethyl esterYield 87%

Procedure

84.6 g. of 1-methyl-4-carboethoxy-5-aminopyrazole and 74.1 g. of orthoformic acid triethyul ester are heated together until the splitting off of ethanol has ended. The oily residue is distilled under oil pump vacuum to obtain 5-[(ethoxy-methylene)amino]-1-methyl-1h-pyrazole-4-carboxylic acid, ethyl ester b.p. 98°-102°; m.p. 32°-34° (yield87%).