Methanamine, N-methoxy-, hydrochloride (1:1) → tert-butyl 1-(methoxy(methyl)carbamoyl)-3-phenyl-5,6-dihydroimidazo[1,5-a]pyrazine-7(8H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere 7-tert-butyl 1-methyl 3-phenyl-5,6-dihydroimidazo[1,5-a]pyrazine-1,7(8H)-dicarboxylate (Intermediate 3A) (1.50 g, 4.20 mmol) was dissolved in THF (6 mL) and N,O-dimethyl-hydroxylamine hydrochloride (1.23 g, 12.59 mmol) was added. The resulting suspension was cooled to −20° C. and a solution of iPrMgCl (2M, 6.3 mL, 12.59 mmol) in THF was added dropwise over 10 min. The mixture was stirred for 20 min at −10° C. and then was quenched with saturated aqueous NH4Cl. The mixture was extracted with EtOAc, dried over anhydrous Na2SO4, filtered and concentrated to provide Intermediate 26A as a white solid (1.35 g, 83%). 1H-NMR (400 MHz, CDCl3) δ: 1.52 (s, 9H), 3.63 (s, 3H), 3.80 (m, 2H), 3.90 (s, 3H), 4.12 (t, 2H), 5.02 (s, 2H), 7.46 (m, 3H), 7.65 (m, 2H); LCMS (+ESI) m/z 387.1 [M+H]+.

Provenance & Evidence