Divided in five microwave vials (30 mL
volume vials): tert-butyl [2-(1-methyl-1H-pyrazol-5-yl)-2-oxoethyl]carbamate
(40 ) (10.0 g, 85% purity, 35.52 mmol) was dissolved in
60 mL of methanol. Potassium cyanide (10.89 g, 167.17 mmol) and ammonium
carbonate (16.06 g, 167.17 mmol) were added. The vials were sealed,
and the mixture was stirred at 80 °C for 2 d. The contents of
the vials were pooled, the salts were filtered off and rinsed with
methanol, and the filtrate was concentrated. The residue was purified
by column chromatography (Machine: Biotage Isolera; column: Biotage
SNAP Ultra 100 g; eluent: DCM/MeOH: 5% MeOH → 30% MeOH; flow:
100 mL/min). Product containing samples were united and the solvents
were evaporated. 8.9 g (100% purity, 81% yield) of the title compound
was obtained. LC–MS (Method 2): Rt = 0.95 min; MS (ESIpos): m/z = 310 [M – H]+.
volume vials): tert-butyl [2-(1-methyl-1H-pyrazol-5-yl)-2-oxoethyl]carbamate
(
60 mL of methanol. Potassium cyanide (10.89 g, 167.17 mmol) and ammonium
carbonate (16.06 g, 167.17 mmol) were added. The vials were sealed,
and the mixture was stirred at 80 °C for 2 d. The contents of
the vials were pooled, the salts were filtered off and rinsed with
methanol, and the filtrate was concentrated. The residue was purified
by column chromatography (Machine: Biotage Isolera; column: Biotage
SNAP Ultra 100 g; eluent: DCM/MeOH: 5% MeOH → 30% MeOH; flow:
100 mL/min). Product containing samples were united and the solvents
were evaporated. 8.9 g (100% purity, 81% yield) of the title compound
was obtained. LC–MS (Method 2): Rt = 0.95 min; MS (ESIpos): m/z = 310 [M – H]+.
