Triethylamine → tert-Butyl 4-chloro-5,6-dihydropyrido(4',3':4,5)thieno(2,3-d)pyrimidine-7(8H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To sulfolane (3.19 L) was added phosphoryl chloride (785 g, 5.12 mol) at rt. Triethylamine (518 g, 5.12 mol) was added dropwise with water-bath cooling. tert-Butyl 4-oxo-3,5,6,8-tetrahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine-7(4H)-carboxylate from Example 10A (525.5 g, 1.706 mol) and additional sulfolane (1.34 L) were added, and the mixture was heated to 70° C. for 2.5 h. The mixture was cooled to it, and triethylamine (967 g, 9.56 mol) was added. A semi-saturated aqueous sodium chloride solution (10 L) was added during which the mixture was cooled with an ice-bath. After stirring at rt for 2 h, the precipitate was collected by suction filtration and washed three times with water (1.5 L). The residue was dried to yield 517 g (93%) of the title compound.

Provenance & Evidence