Triethylamine → 4-(Azetidin-1-ylcarbonyl)-2-bromo-1,3-thiazole

Participants

Reaction Steps

To a solution of 2-bromothiazole-5-carboxylic acid (752 mg, 3.62 mmol) in DCM (10 mL) was slowly added oxalyl chloride (0.38 mL, 4.34 mmol) and then DMF (1 drop). The mixture was stirred for 4 hours, following which the organics were removed in vacuo, and the residues azeotroped with toluene (10 mL). The crude material was dissolved in DCM (10 mL) and slowly added to a stirred suspension of azetidine hydrochloride (404 mg, 4.34 mmol) and triethylamine (1.8 mL, 13 mmol) in DCM (25 mL). The mixture was stirred at RT for 2 hours before the organics were removed in vacuo. The residue was partitioned between ethyl acetate (50 mL) and water (25 mL), the organic layer washed with brine (25 mL), dried (MgSO4) and evaporated to a residue which was chromatographed on silica, eluting with 40% ethyl acetate in iso-hexane, to give the desired compound (500 mg).

Provenance & Evidence