Hydrazine → 3-Amino-6-bromopyrazine-2-carbohydrazide

Temperature

50 °C

Hydrazine hydrate (23.59 mL, 480.75 mmol) was added dropwise to a stirred mixture of methyl 3-amino-6-bromopyrazine-2-carboxylate (100 g, 418.04 mmol) in EtOH (2 L). The mixture was heated at 50° C. under nitrogen. The resulting thick suspension was stirred at 50° C. for 16 hours. Further hydrazine (2.5 mL) was added in one portion and the suspension was stirred at 50° C. for a further 24 hours. Ethanol (500 mL) was charged to the thick reaction mixture and the mixture was allowed to cool to room temperature. The resulting suspension was filtered and the solid washed with ethanol (1 L) and dried in vacuo to give 3-amino-6-bromopyrazine-2-carbohydrazide (98 g, quantitative) as a cream solid: 1H NMR Spectrum: (DMSO-d6) 4.52 (2H, s), 7.59 (2H, s), 8.30 (1H, s), 9.74 (1H, s): Mass Spectrum [M+H]+=232.

1. stirringthe suspension was stirred at 50° C. for a further 24 hours
2. temperatureto cool to room temperature
3. filtrationThe resulting suspension was filtered
4. washthe solid washed with ethanol (1 L)
5. customdried in vacuo

ORD record

ord-f664cd355a22464593e2aa6a05a32d98

Source dataset

uspto-grants-2015_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09155727B2