4-[2-(4-Fluorophenyl)ethynyl]-2-(methylthio)pyrimidine → 2-(4-fluorophenyl)-4,5-dihydro-3-[2-(methylthio)-4-pyrimidinyl]-7H-pyrazolo[1,5-c][1,3]oxazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-[2-(4-fluorophenyl)ethynyl]-2-(methylthio)pyrimidine (i.e. the product of Example 1, Step A) (1.26 g, 5.16 mmol) and 3-hydroxy-7H-[1,2,3]oxadiazolo[3,4-c][1,3]oxazin-8-ium inner salt (i.e. the product of Step C) (0.99 g, 6.96 mmol) in mesitylene (20 mL) was heated at 160° C. for 24 h. The reaction mixture was concentrated under reduced pressure, and the residual oil was purified by medium pressure liquid chromatography using 0-100% ethyl acetate in hexanes as eluant to give 290 mg of the title compound as a white solid.

Provenance & Evidence