2-Hydroxy-6-chloroquinoxaline → 6-chloro-3,4-dihydroquinoxalin-2(1h)-one

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Reaction Steps

Sodium borohydride (5.10 g) is added to a mixture of 6-chloro-1,2-dihydroquinoxalin-2-one (5.60 g), and ethanol (200 ml). The resultant solution is stirred for 2.5 hr at 20°-25°. The material is partitioned between water and ethyl acetate, the phases are separated, the organic phase is dried over magnesium sulfate and concentrated under reduced pressure to give a solid which is recrystallized from ethyl acetate/hexane to give the title compound, mp 171°-174°; IR (mineral oil) 2953, 2925, 1687, 1517, 1408, 1307 and 1299 cm-1 ; NMR (CDCl3 -MeOD) 6.6-6.8 and 3.95 δ; MS (m/z) 182, 153.

Provenance & Evidence