rac-3,4-dihydro-2-ethynyl-2,5,7,8-tetramethyl-2H-1-benzopyran-6ol → rac-3,4-Dihydro-6-[(3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)ethynyl]-4-(trifluoroacetyl)-2H-1,4-benzoxazine

Participants

Reaction Steps

This compound was prepared by coupling rac-3,4-dihydro-2-ethynyl-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol (1,15 g or 5 mmol) with 4-(trifluoroacetyl)-3,4-dihydro-6-iodo-2H-1,4-benzoxazine (1.95 g or 5.5 mmol) under the conditions described in Example 15. The product was isolated by chromatography over the 40 fold amount of silica gel methylene chloride. It was crystallized from ether/hexane and recrystallized twice from methanol to give colorless crystals with m.p. 153°-155°.

Provenance & Evidence