(5S)-3-methyl-5-phenyl-5,6-dihydro-2H-1,4-oxazin-2-one → HCID 67442474, compound

Participants

Reaction Steps

To a solution of (5S)-3-methyl-5-phenyl-5,6-dihydro-2H-1,4-oxazin-2-one (1.70 g, 9.0 mmol, 1.0 equiv.) in anhydrous dichloromethane (60 mL) under an atmosphere of nitrogen was added PtO2 (170 mg, 0.1 equiv.). The mixture was consecutively degassed and purged three times with hydrogen and then stirred for 5 hours under an atmosphere of hydrogen. Filtration through a short pad of CELITE® diatomaceous earth and removal of solvent from the filtrate in vacuo yielded the crude product which was purified by recrystallisation in dichloromethane, diethyl ether and hexane to furnish the title compound as white needles (1.26 g, 74%); m.p. 81.0-82.0° C. (lit. m.p. 81.0-82.0° C.); v(max)(KBr) 3314 (N—H), 2981 (C—H), 1736 (C═O), cm−1; δH (250 MHz, CDCl3) 7.43-7.26 (5H, m, Ph); 4.42-4.23 (3H, m, CHCl2), 3.88 (1H, q, /6.76 Hz, CHCH3), 1.80 (1H, br, NH), 1.50 (3H, d, J 6.76 Hz, CH3); δc (62.5 MHz, CDCl3) 170.7, 138.1, 129.3, 129.1, 127.5, 75.4, 58.2, 55.4, 19.0; m/z (CL, NH3), 192 (MH+, 30%), 147 (68%), 132 (64%), 104 (100%), and 91 (10%); HRMS for C11H13NO2 requires 192.1025 found 192.1019. [α]D20 +88.8 (c 0.96 CHCl3) (lit. [α]D20 +92.3 (c 0.84 CHCl3)).

Provenance & Evidence