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US 8,710,218 B2Granted
Process for preparation of Efavirenz
AssigneeLupin Limited
InventorsGirij Pal Singh, Gurvinder Pal Singh, Pravin Mahajan, Ganesh Salunke, Dabeer Karnalkar
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Abstract
An improved process for Efavirenz, which has several advantages over reported methods like low cost, high yield, better optical purity and industrial feasibility.
Claims11
A process for preparation of optically pure (−)6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one having formula:
- the process comprising reacting optically pure (−)2-(2-amino-5-chlorophenyl)-4-cyclopropyl-1,1,1-trifluoro-3-butyn-2-ol, of formula
- with a carbonyl delivering agent in tetrahydrofuran to give optically pure (−)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one.
A process for preparation of optically pure (−)6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one having formula:
- the process comprising the step;
- reacting optically pure (−)2-(2-amino-5-chlorophenyl)-4-cyclopropyl-1,1,1-trifluoro-3-butyn-2-ol, of formula
- with a carbonyl delivering agent in an aprotic solvent, to give optically pure (−)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one;
- wherein the carbonyl delivering agent is diphenylcarbonate or triphosgene.
1 more element
Dependencies are inferred from the claim text.