Sodium borohydride → 6-amino-4,4-diethyl-1-methyl-1,4-dihydro-2H-3,1-benzoxazin-2-one

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 4,4-diethyl-1-methyl-6-nitro-1,4-dihydro-2H-3,1-benzoxazin-2-one (3.74 g, 14.15 mmol) and 5% palladium on carbon (0.20 g) in methanol (35 mL) at 0° C. was added sodium borohydride (10.70 g, 28.30 mmol) portionwise. After stirring 1 hr at 0° C., the reaction was quenched with ice and ammonium chloride solution (sat.) and extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with brine and dried over magnesium sulfate. Solvent was removed and trituration of the residue with ether gave 6-amino-4,4-diethyl-1-methyl-1,4-dihydro-2H-3,1-benzoxazin-2-one as a yellow solid (2.67 g, 81%). 1H NMR (DMSO-d6): δ 6.78 (d, J=8.6 Hz, 1H), 6.56 (m, 1H), 6.40 (d, J=2.4 Hz, 1H), 4.93 (s, 2H), 3.18 (s, 3H), 1.99 (m, 4H), 0.80 (t, J=7.3 Hz, 6H); MS (ESI) m/z 235 ([M+H]+); Anal. calcd for C13H18N2O2: C, 66.64; H7.74; N 11.96. Found: C, 64.97; H, 7.67; N, 11.62.

Provenance & Evidence