Triethylamine → Methyl 1-(3-chloropyridin-2-yl)-3-{[(methylsulfonyl)oxy]methyl}-1H-pyrazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl 1-(3-chloropyridin-2-yl)-5-hydroxy-3-(hydroxymethyl)-4,5-dihydro-1H-pyrazole-5-carboxylate (28.5 g, 0.1 mol) and 15 g of triethylamine were introduced as initial charge in 150 ml of THF and the solution was cooled to 5° C. (11.4 g, 0.1 mol) of mesyl chloride were added at 0-5° C. within 20 min and the mixture was after-stirred at 0° C. for 2 hours. The reaction mixture was diluted with water and the product was extracted with ethyl acetate. The ethyl acetate solution was washed, dried and concentrated by evaporation. The viscous residue (product weight 31 g) contained, according to LC/MS, 98% of the product.

Provenance & Evidence