Triethylamine → 1-(3-Bromo-phenyl)-3,5-diethyl-1H-pyrazole-4-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 7.10 g (35.5 mmol) of (E and/or Z)-3-methoxy-2-propionyl-pent-2-enoic acid methyl ester in 10 ml of MeOH was added to a solution of 8.09 g (35.5 mmol) of 3-bromophenylhydrazine hydrochloride in 150 ml of MeOH and the mixture was cooled to −20° C. To this mixture was added a solution of 3.79 g=5.22 ml (37.2 mmol) of Et3N in 40 ml of MeOH drop by drop and the reaction was then warmed up to RT. After 20 hours, it was poured into crashed ice and extracted twice with Et2O; the organic phases were washed with water, dried over magnesium sulfate, filtered and evaporated to give 7.62 g of the title compound as light red oil. MS: 337.1 (MH+, 1 Br).

Provenance & Evidence