Triethylamine → tert-butyl 4-chloro-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate

Participants

Reaction Steps

A mixture of PPh3 (81.4 g, 310 mmol) and N-chlorosuccinimide (41.4 g, 310 mmol) in dioxane (850 mL) was stirred at ambient temperature for 30 minutes. To this suspension was added tert-butyl 4-hydroxy-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate and the mixture stirred at 50° C. for 18 hours. The mixture was subsequently treated with triethylamine (25 mL, 183 mmol) and the resulting brown solution concentrated. The black oil was dry packed onto silica gel and purified by chromatography eluting with 15-20% EtOAc/Hexanes to give the title compound as a yellow gum.

Provenance & Evidence