Water → Efavirenz

Participants

Reaction Steps

K2CO3 (13.3 g, 95.8 mmol) powder was added to a solution of (S)-2-(5-chloro-2-((1S,4R)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carboxamido) phenyl)-4-cyclopropyl-1,1,1-trifluorobut-3-yn-2-yl 1-chloroethyl carbonate (7, R1 is 4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptyl, R3 is 1-chloroethyl, 36.8 g, 63.9 mmol) in N,N-dimethylformamide (150 mL). The reaction mixture was stirred at room temperature overnight. Methyl t-butyl ether (300 mL) and water (300 mL) were added to the mixture, and the resulting layers were separated. The organic layer was washed with brine and evaporated to 60 mL then petroleum ether (200 mL) was added. The resulting mixture was filtered and rinsed with petroleum ether to give (S)-6-chloro-4-(cyclopropylethynyl)-4-(trifluoromethyl)-1,4-dihydro-2H-3,1-benzoxazin-2-one (Efavirenz, 1) as an off-white solid.

Provenance & Evidence