Diisopropylethylamine → HCID 90010077, compound

Participants

Reaction Steps

Step-3: 5-(5-Bromo-6-ethylpyridin-3-yl)-1,3,4-oxadiazol-2(3H)-one: To a stirred and cooled (0° C.) solution of 5-bromo-6-ethylnicotinohydrazide (2.50 g, 10.24 mmol, 1.0 eq) and diisopropylethylamine (3.58 mL, 20.48 mmol, 2.0 eq) in DCM (20 mL) was added a solution of triphosgene (1.21 g, 4.10 mmol, 0.4 eq) in DCM (10 mL) over a period of 10 min. The resulting mixture was stirred for 1 h at the same temperature. The reaction mixture was then diluted with DCM (50 mL) and washed with water (50 mL), aqueous sodium bicarbonate (10%, 50 mL), brine (50 mL), dried (Na2SO4) and filtered. The filtrate was evaporated under vacuum to afford 1.60 g (58%) of the desired product as a white solid. 1HNMR (400 MHz, DMSO) δ 8.83 (d, J=1.5 Hz, 1H), 8.25 (d, J=1.5 Hz, 1H), 2.92 (q, J=7.0 Hz, 2H), 1.21 (t, J=7.0 Hz, 3H); ESI-MS (m/z) 270, 272 [(MH)+ Br79, 81].

Provenance & Evidence