Triethylamine → 5-Bromoacetamido-3-methoxy-[1,2,4]thiadiazole

Participants

Reaction Steps

To an ice-cooled solution of 5-amino-3-methoxy-[1,2,4]thiadiazole (1.31 g, 10 mmol) in THF (25 mL) was added triethylamine (2.22 g, 11 mmol) followed by dropwise addition of bromoacetyl bromide (1.52 g, 15 mmol). The resulting mixture was stirred at room temperature for 16 h. The mixture was diluted with water (25 mL) and ethyl acetate (50 mL). The aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers was dried (sodium sulfate), filtered and concentrated in vacuo. Purification by column chromatography on silica gel using a solvent gradient of a mixture of dichloromethane and methanol (98/2, 97/3 and 96/4) afforded 3-methoxy-5-bromoacetamido-[1,2,4]thiadiazole as a white solid (1.26 g, 50%). M.p. 198-199° C.; 1H-NMR (CDCl3) δ 13.10 (br. s, 1H, NH), 4.28 (s, 2H, CH2), 4.11 (s, 3H, OMe); 13C-NMR (CDCl3) δ 176.8 (C3), 166.9 (C5), 166.6 (C═O), 56.9 (OMe), 25.9 (CH2).

Provenance & Evidence