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

Participants

Reaction Conditions

Reaction Steps

Under argon 2.10 g (7.85 mmol) of methyl 2-(3-chloropyridin-2-yl)-5-hydroxymethyl-2H-pyrazole-3-carboxylate are introduced in 13 ml of dichloromethane and this initial charge is cooled to 0° C. and admixed dropwise in succession with 1.64 ml (11.8 mmol) of triethylamine and 0.67 ml (8.63 mmol) of methanesulphonyl chloride. It is stirred at this temperature for 30 minutes, diluted with 50 ml of dichloromethane and washed successively with 50 ml each of saturated aqueous sodium hydrogen sulphate solution, 10 percent strength aqueous hydrochloric acid and saturated aqueous sodium chloride solution. The organic phase is dried over magnesium sulphate and then the solvent is removed on a rotary evaporator.

Provenance & Evidence