6-bromo-8-fluoro-[1,2,4]triazolo[4,3-a]pyridine-3(2H)-thione synthesis

Yield:1427473-77-5 19.3%

Reaction Conditions:

in N,N-dimethyl-formamide at 0 - 85; for 3 h;

Steps:

6-Bromo-8-fluoro-[1,2,4]triazolo[4,3-a]pyridine-3-thiol (Intermediate H)

To a solution of H.i (15g, 72.8 mmol) in anhydrous DMF (150ml) was added di(1 H- imidazol-1-yl)methanethione (12.98 g, 72.8 mmol) by portions at 0°C, after the addition was completed, the mixture was heated to 85 °C and stirred for about 3 hr. The solvent was evaporated under reduced pressure and the residue was recrystallized from DCM/MeOH(5:1 ) to give pure desired product as yellow solid (3.5g, yield 19.3%). LCMS (method A): [M-H]^"= 246, 248, f_R = 2.10 min. ¹H-NMR (400MHz, DMSO-d₆) δ ppm 14.98 (s, 1 H), 8.24 (s, 1 H), 7.75 (d, 1 H).

References:

WO2013/38362,2013,A1 Location in patent:Page/Page column 81