1,1'-Carbonyldiimidazole → tert-butyl 2-oxo-2-(1-phenyl-3,4-dihydropyrrolo[1,2-a]pyrazin-2(1H)-yl)ethylcarbamate

Participants

Reaction Steps

(1.1 g, 7.0 mmol) of CDI were added to a solution of Boc-glycine (1.2 g, 6.7 mmol) in DCE (20 ml), and stirring was carried out for 100 min at RT. (1.3 g, 6.7 mmol) of 1-phenyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine (A2) were then added, and stirring was carried out for a further 2 h at RT. The mixture was then heated for 2 h at 50° C. (450 mg, 2 mmol) of Boc-glycine imidazolide were subsequently added, and the mixture was heated for 2 h under reflux. After cooling to RT, washing was carried out with, in succession, a 5% aq. sodium carbonate solution, a 5% aq. citric acid solution, water and brine. The organic phase was dried over MgSO4, filtered and concentrated in vacuo. CC (DCE) with the residue yielded 1.4 g (4.1 mmol, 61%) of tert-butyl 2-oxo-2-(1-phenyl-3,4-dihydropyrrolo[1,2-a]pyrazin-2(1H)-yl)ethylcarbamate.

Provenance & Evidence