Lithium Hydroxide → 1-Methyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylic acid

Participants

Reaction Steps

To a solution of 1-methyl-5-pyrrol-1-yl-1H-pyrazole-4-carboxylic acid ethyl ester (Maybridge plc, Cornwall, UK; 20 g, 91.2 mmol) in methanol (100 mL) and water (100 mL) was added LiOH (2.4 g, 100.3 mmol). The reaction mixture was stirred at reflux for 4 hours and then concentrated under reduced pressure to remove the methanol. The residue was diluted with water, acidified to pH 2 with concentrated HCl (9 mL), and extracted with ethyl acetate. The combined extracts were evaporated in vacuo to give 1-methyl-5-pyrrol-1-yl-1H-pyrazole-4-carboxylic acid which was used without further purification.

Provenance & Evidence