Triethylamine → Methanesulfonic acid pyrazolo[1,5-a]pyridin-2-ylmethyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of methanesulfonyl chloride (0.149 g, 0.13 mmol) in dichloromethane (2 mL) was added to a solution of pyrazolo[1,5-a]pyridin-2-yl-methanol (0.148 g, 0.1 mmol) and triethylamine (0.303 g, 0.3 mmol) in dichloromethane (3 mL) at −10° C. under N2. After the addition was complete, the mixture was stirred at −10° C. for 1 h. Ice water (10 mL) was added, and the organic layer was separated, dried over sodium sulfate, filtered and concentrated under vacuum to give methanesulfonic acid pyrazolo[1,5-a]pyridin-2-ylmethyl ester as a yellow oil, which was used for the next step without further purification. A solution of this material (0.22 g, 0.1 mmol) in dry dichloromethane (2 mL) was added to a solution of 1-methyl-4-phenyl-1,3-dihydro-imidazole-2-thione (0.190 g, 0.1 mmol) and DIPEA (0.303 g, 0.3 mmol) in dry DMF (3 mL) at −10° C. under N2. The mixture was stirred at 0° C. for 2 hours, and was then concentrated under reduced pressure. The residue was purified by preparative HPLC to afford the title compound (50 mg, 15%). LC-MS: m/z=321.1 (MH+), tR=2.16 min, method F.

Provenance & Evidence