Ethyl imino(2-bromopyridin-5-yl)acetate → 2-bromo-5-[(1, 3-dibutyl-1H-1,2,4-triazol-5-yl)methyl]pyridine

Participants

Reaction Steps

Under nitrogen, a solution of 1.2 g (5 mmol) of imidate ester from step 6 and 850 mg (5 mmol) of N2 -butyl valeric acid hydrazide from step 2 in 25 mL of absolute methanol was stirred for 24 h at ambient temperature. The methanol was removed in vacuo and replaced with 25 mL of anhydrous toluene. The reaction vessel was equipped with a Dean-Stark trap and the reaction stirred at reflux for 48 h. Concentration in vacuo produced the crude product residue. Purification by silica gel chromatography (Waters Prep-500A) using ethyl acetate/hexane (60:40) gave 700 mg (40%) of 2-bromo-5-[(1, 3-dibutyl-1H-1,2,4-triazol-5-yl)methyl]pyridine as an oil: NMR (CDCl3) δ 0.88 (t, J=7Hz, 3H), 0.92 (t, J=7Hz, 3H), 1.25-1.75 (m, 8H), 2.67 (t, J=8Hz, 2H), 3.93 (t, J= 7Hz, 2H), 4.05 (s, 2H), 7.43 (s, 1H), 7.44 (s, 1H), 8.27 (s, 1H); MS (FAB)m/e (rel intensity) 353 (50), 351 (50), 297 (100), 295 (100), 215 (40), 160 (90), 158 (90), 138 (70).

Provenance & Evidence