4-carbamoyl-2-(6-methoxy-4H-quinazolin-3-yl)butanoic acid → 3-(6-methoxy-4H-quinazolin-3-yl)piperidine-2,6-dione

Participants

Reaction Steps

A solution of 1.20 g of the crude product from stage 4 in 7 ml of acetic anhydride and 7 ml of acetyl chloride was stirred for 5 hours at 70° C. and then concentrated by evaporation in vacuo. The residue was taken up in 20 ml of methanol and stirred for 1 hour with Amberlyst A-21 ion exchanger. After filtration the filtrate was concentrated by evaporation in vacuo and the residue was purified by flash chromatography with chloroform/methanol (4/1) as eluent. The free base of the title compound thereby obtained was dissolved in 4 ml of methanol and 0.5 ml of a saturated solution of HCl gas in diethyl ether followed by 150 ml of diethyl ether were added to the solution. The salt formed was separated and dried in vacuo, 0.29 g (23% of theory referred to L-glutamine in stage 4) of the title compound being obtained.

Provenance & Evidence