Thionyl Chloride → Ethyl 2-(5-(Chloromethyl)-3-nitro-1H-pyrazol-1-yl)acetate

Participants

Reaction Conditions

Reaction Steps

To a mixture of 151a (1.50 g, 6.55 mmol) in CHCl3 (60 mL) cooled at 0° C. was slowly added SOCl2 (2.34 g, 19.6 mmol) while maintaining the internal temperature below 5° C. This reaction mixture was warmed to 50° C. and stirred at this temperature for 3 h. It was then cooled to 0° C. and quenched with water. The organic layer was separated and evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 30:1 dichloromethane/methanol to afford 151b (1.1 g, 68%) as a yellow solid. MS-ESI: [M+H]+ 247.9

Provenance & Evidence