1-Butyl-6-ethoxycarbonyl-5-(4-fluorophenyl)-7-isopropyl-2,4-dioxo-1,2,3,4,5,8-hexahydro-pyrido(2,3-d)pyrimidine → 1-Butyl-6-ethoxycarbonyl-5-(4-fluorophenyl)-7-isopropyl-2,4-dioxo-1,2,3,4-tetrahydro-pyrido(2,3-d)pyrimidine

Participants

Reaction Steps

11.35 g (50 mmol) of 2,3-dichloro-4,5-dicyanobenzoquinone are added to a mixture of 21.5 g (50 mmol) of the compound from Example 2 in 800 ml of dichloromethane and the mixture is stirred at room temperature for 1 h. The solution is filtered from a beige precipitate, the filtrate is washed four times with water, the organic phase is dried over sodium sulphate, filtered through a thin layer of active carbon and the filtrate is concentrated in vacuo. The residue is crystallized from ether/petroleum ether.

Provenance & Evidence