Methyl iodide → (E)-3-{1'-tert-butoxycarbonyl-3,4-dihydro-3-methyl-4-oxo-spiro[2H-(1,3)-benzoxazine-2,4'-piperidin]-6-yl}-acrylic acid methyl ester

Participants

Reaction Steps

(E)-3-{1′-Tert-butoxycarbonyl-3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,4′-piperidin]-6-yl}-acrylic acid methyl ester (4.02 g, 10.0 mmol) was dissolved in DMF (35 ml) and added to a stirred suspension of NaH (60% oil dispersion, 480 mg, 12 mmol) in DMF (35 ml) at 4° C. After 10 min CH3I (2.13 g, 15.0 mmol) was added, the resulting mixture was stirred at RT for 30 min and then partitioned between saturated aqueous solution of NH4Cl and AcOEt. The organic phase was rinsed with water, dried over Na2SO4 and evaporated. The crude mixture was purified by trituration in AcOEt and petroleum ether to give (E)-3-{1′-tert-butoxycarbonyl-3,4-dihydro-3-methyl-4-oxo-spiro[2H-(1,3)-benzoxazine-2,4′-piperidin]-6-yl}-acrylic acid methyl ester (3.66 g).

Provenance & Evidence