Acetyl chloride → Acetic acid 7-allyl-1H-indazol-6-yl ester

Participants

Reaction Steps

A solution of the product from Step B (6.35 g, 37 mmol) in THF (100 mL) containing triethylamine (7.6 ml, 55 mmol) was stirred for 5 minutes at ambient temperature, cooled to 0° C. (ice bath), and acetyl chloride (2.63 mL, 37 mmol) was added. The mixture was stirred at 0° C. for 2 hours, additional acetyl chloride (0.26 mL, 3.7 mmol) was added, and the mixture stirred for 10 min at which point another portion of acetyl chloride (0.26 ml, 3.7 mmol) was added and stirring continued for 15 min. The reaction was quenched with triethyl amine (1 mL) and saturated aqueous sodium bicarbonate (100 mL) and extracted with ethyl acetate (100 mL). The extract was dried (MgSO4) and evaporated to an oil (9.27 g) which was purified by chromatography (silica, 10% to 50% EtOAc/hexane) to give a white solid, (3.50 g, 44%): LC/MS (+APCI) m/z 217 (M+H).

Provenance & Evidence