(3R)-3-ethyl-7-fluoro-4-(4-hydroxybenzoyl)-1-methyl-3,4-dihydroquinoxalin-2(1H)-one → (3R)-1-butyl-3-ethyl-6-fluoro-4-(4-hydroxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one

Participants

Reaction Steps

(3R)-1-Butyl-3-ethyl-6-fluoro-4-(4-methoxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one was treated according to the procedure for the preparation of (3R)-3-ethyl-7-fluoro-4-(4-hydroxybenzoyl)-1-methyl-3,4-dihydroquinoxalin-2(1H)-one (see Example 1) to yield (3R)-1-butyl-3-ethyl-6-fluoro-4-(4-hydroxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one (94%). [α]D25=−268° (c=0.0103G/ML, CHCl3); MS (ESI) m/z 371 ([M+H]+); MS (ESI) m/z 369 ([M−H]−); HRMS: calcd for C21H23FN2O3, 370.1693; found (ESI_FT), 371.17594; Anal. Calcd for C21H23FN2O3: C, 68.09; H, 6.26; N, 7.56. Found: C, 67.96; H, 6.60; N, 7.67.

Provenance & Evidence