Triethylamine → HCID 67001155, compound

Participants

Reaction Steps

A mixture of 5-(4-chloro-3-methyl-phenyl)-3-iodo-7-difluoromethyl-pyrazolo[1,5-a]pyrimidine (7.01 g, 16.7 mmol), trimethylsilylacetylene (4.16 mL, 30.0 mmol) and triethylamine (4.66 mL, 33.4 mmol) in N,N-dimethylformamide (18 mL) was stirred for 10 min at room temperature while being purged with Argon, then PdCl2(PPh3)2 (117 mg, 1 mol %), PPh3 (44 mg, 1 mol %) and CuI (10 mg, 0.3 mol %) were added. Stirring was continued at 90° C. for 4.5 h. The reaction mixture was cooled to room temperature, diluted with water (100 mL) and extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with water (2×50 mL) and brine (70 mL), dried (MgSO4), evaporated and further purified by column chromatography on silica gel (dischloromethane/heptane 7:3) to give 5-(4-chloro-3-methyl-phenyl)-7-difluoromethyl-3-trimethylsilanylethynyl-pyrazolo[1,5-a]pyrimidine (4.73 g, 73%) as an orange solid, which was dissolved in THF (74 mL) and MeOH (56 mL), while stirring at 0° C. potassium carbonate (168 mg, 1.22 mmol) was added and the mixture was stirred at 0° C. for 5 h. The mixture was diluted with ice water (250 mL) and extracted with TBME (3×250 mL). The combined organic layers were washed with brine (200 mL), dried (MgSO4) and evaporated. The crude product was further purified by flash chromatography on silica gel (heptane/EtOAc) followed by crystallization fromethyl acetate/hexane to give 5-(4-chloro-3-methyl-phenyl)-3-ethynyl-7-difluoromethyl-pyrazolo[1,5-a]pyrimidine (3.8 g, 72%) as a light brown solid. MS (EI) 317.2 [(M)+]; mp 143° C.

Provenance & Evidence