Hydrochloric Acid → 1-(3-chloropyridin-2-yl)-3-{(E)-2-[5-(trifluoromethyl)-2H-tetrazol-2-yl]vinyl}-1H-pyrazole-5-carboxylic acid

Participants

Reaction Steps

88.7 mg (0.23 mmol) of methyl 1-(3-chloropyridin-2-yl)-3-{(E)-2-[5-(trifluoromethyl)-2H-tetrazol-2-yl]vinyl}-1H-pyrazole-5-carboxylate and methyl 1-(3-chloropyridin-2-yl)-3-{(E)-2-[5-(trifluoromethyl)-1H-tetrazol-1-yl]vinyl}-1H-pyrazole-5-carboxylate in a ratio of 66:34 were dissolved in 5.0 ml of ethanol, and 26.6 mg (0.29 mmol) of 45% strength aqueous sodium hydroxide solution were added. After 1 hour of stirring at room temperature, the mixture was diluted with water and acidified with dilute hydrochloric acid. The aqueous phase was extracted repeatedly with ethyl acetate and dried over magnesium sulphate. The solvent was distilled off under reduced pressure, which gave 43 mg (48% of theory) of 1-(3-chloropyridin-2-yl)-3-{(E)-2-[5-(trifluoromethyl)-2H-tetrazol-2-yl]vinyl}-1H-pyrazole-5-carboxylic acid and 1-(3-chloropyridin-2-yl)-3-{(E)-2-[5-(trifluoromethyl)-1H-tetrazol-1-yl]vinyl}-1H-pyrazole-5-carboxylic acid in a ratio of 70:30. (logP: 2.79/2.86; MH+: 386.0/386.0; 1H-NMR (400 MHz, CD3CN, δ, ppm): 7.40 (m, 1H), 7.59 (m, 1H), 7.75 (m, 1H), 8.05 (m, 1H), 8.31 (m, 1H), 8.53 (m, 1H).)

Provenance & Evidence