6-Bromo-2-methyl[1,2,4]triazolo[1,5-a]pyridine

1202704-57-1

108-24-7

7169-95-1

The general procedure for the synthesis of 6-bromo-2-methyl-[1,2,4]triazolo[1,5-A]pyridine from the compound (CAS:1202704-57-1) and acetic anhydride was as follows: concentrated hydrochloric acid (1 mL) was slowly added to a solution of acetic anhydride (9 mL) of compound 13 (7.01 g), followed by heating and refluxing for 14 hours. Upon completion of the reaction, the reaction mixture was neutralized with aqueous NaHCO3, followed by extraction with methanol-chloroform (1:9, v/v). The organic phase was washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The resulting residue was recrystallized from ethanol to give 2.985 g of compound 14 as colorless needle-like crystals. The recrystallized mother liquor was further purified by column chromatography (eluent: hexane-ethyl acetate (1:1, v/v)) to give 401 mg of Compound 14. total yield: 3.385 g (92% yield). The properties of compound 14 were as follows: colorless acicular crystals; melting point: 154.5-155 °C (hexane-CHCl3); 1H-NMR (300 MHz, CDCl3) δ 2.60 (s, 3H), 7.54 (d, J=1.2 Hz, 1H), 8.64 (dd, J=1.1 Hz, 1H); LRMS m/z 211,213 (M+) , relative intensities 96,100), 170,172 (13,12), 156,158 (10,7), 143,145 (10,6), 64 (58), 42 (18).