Sodium Hydroxide → 1,1-Dimethylethyl 4-[6-(2,2-difluoroethoxy)-2,4-dioxo-3,4-dihydroquinazolin-1(2H)-yl]piperidine-1-carboxylate

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Reaction Steps

2.5 g of 1,1-dimethylethyl 4-{carbamoyl[4-(2,2-difluoroethoxy)-2-(methoxycarbonyl)phenyl]amino}piperidine-1-carboxylate obtained in stage 3.4 in solution in a mixture of 10 ml of dioxane and 5 ml of a 1N aqueous NaOH solution are irradiated under a microwave field at 130° C. for 30 min. Extraction is carried out with AcOEt and the extract is neutralized with a 1N aqueous HCl solution, washed with water, dried over MgSO4, filtered and evaporated under reduced pressure. The residue obtained is triturated in an AcOEt/pentane mixture to give the expected product. The same reaction is reproduced with 2 other lots of 2.5 g of 1,1-dimethylethyl 4-{carbamoyl[4-(2,2-difluoroethoxy)-2-(methoxycarbonyl)phenyl]amino}piperidine-1-carboxylate obtained in stage 3.4 to give, in total, 5.63 g of expected product.

Provenance & Evidence