tert-Butyl carbazate → N'-(oxan-4-yl)(tert-butoxy)carbohydrazide

Participants

Reaction Steps

Tetrahydro-4H-pyran-4-one (9.69 g, 97 mmol) was added to a solution of 1,1-dimethylethyl hydrazinecarboxylate (14.07 g, 106 mmol) in methanol (100 mL) and stirred at room temperature for 3 h. The solvent was removed in vacuo, and the crude residue was suspended in acetic acid (140 mL). Next added sodium cyanoborohydride (6.69 g, 106 mmol) in portions over 3 minutes. The contents were stirred at room temperature for 60 h. The solvent was removed in vacuo, and the crude residue was suspended in DCM (100 mL). The reaction mixture was adjusted to pH 7 with 6N NaOH. The layers were separated, and the aq. layer extracted with DCM. The combined organic layers were washed with saturated NaHCO3, and brine. The organic layer was dried over MgSO4, filtered, and concentrated in vacuo to afford the product as a solid, 18.4 g (88%). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.22 (m, 2 H), 1.39 (s, 9 H), 1.43-1.48 (m, 1 H), 1.59-1.69 (m, 2 H), 2.82-2.98 (m, 1 H), 3.20-3.32 (m, 2 H), 3.80 (d, J=11.62 Hz, 2 H), 4.36 (br. s., 1 H), 8.07-8.34 (m, 1 H).

Provenance & Evidence