Formaldehyde → 1,1-Dimethylethyl [5-(methylamino)-2-(methyloxy)phenyl]carbamate

Participants

Reaction Conditions

Reaction Steps

A suspension of 1,1-dimethylethyl [5-amino-2-(methyloxy)phenyl]carbamate (1.94 g, 8.14 mmol), paraformaldehyde (1.222 g, 40.7 mmol), and sodium methoxide (2.199 g, 40.7 mmol) in methanol (50 ml) was maintained at 50° C. for 16 hours, cooled, sodium borohydride (0.924 g, 24.42 mmol) was added portionwise, and the solution was re-heated to 50° C. and maintained for an additional 24 hours. The solution was cooled, diluted with ethyl acetate, saturated sodium bicarbonate, and the organic layer was dried over sodium sulfated, filtered, taken to a residue under reduced pressure, and purified by column chromatography to afford 1,1-dimethylethyl [5-(methylamino)-2-(methyloxy)phenyl]carbamate (2.15 g, 8.52 mmol, quant. Yield) as a pale yellow oil. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.58 (s, 1 H), 7.10 (d, J=1.6 Hz, 1 H), 6.76 (d, J=8.8 Hz, 1 H), 6.14 (dd, J=8.7, 2.7 Hz, 1H), 5.07-5.31 (m, 1 H), 3.61-3.74 (m, 3 H), 2.60 (d, J=4.4 Hz, 3 H), 1.44 (s, 9 H).

Provenance & Evidence