1-(5-broMo-3-chloropyrazin-2-yl)hydrazine synthesis

Yield:850421-08-8 71%

Reaction Conditions:

with hydrogenchloride in ethanol;water at 100; for 2 h;

Steps:

5-bromo-3-chloro-2-hydrazinylpyrazine H-1

N'-(5-bromo-3-chloropyrazin-2-yl)-2,2,2-trifluoroacetohydrazide G-1 (1.59 g; 4.97 mmol) is dissolved in 30 ml EtOH and treated with 3 ml conc. HCl. It is stirred for 2 hours at 100° C. The reaction mixture is cooled down, diluted with water and then the pH adjusted to 8 with saturated NaHCO3 solution. The water phase is extracted with EtOAc, the organic layer dried over MgSO4 and evaporated to dryness. Yield: 71% (945 mg; 3.51 mmol)
HPLC-MS: (M-H)^-=221/223/225; t_Ret=1.32 min; method FECB5.

References:

US2014/142098,2014,A1 Location in patent:Paragraph 0245 - 0248