Dimethyl Sulfide → 3-[5-tert-Butyl-3-isoxazolyl]-4-hydroxy-1-methyl-2-imidazolidinone

Participants

Reaction Steps

To a 100 ml. round bottom flask equipped with a magnetic stirring bar and a gas dispersion tube were added 8.89 g. of 1-(5-t-butylisoxazol-3-yl)-3-allyl-3-methylurea, 38 ml. of methanol and 38 ml. of dichloromethane. The solution was cooled to -10°, and approximately 40 millimoles of ozone was introduced into the mixture through the gas dispersion tube in a stream of dry air with good mixing over 1 hour. The temperature of the mixture gradually warmed to about 3° as the reaction went on. When all of the ozone had been added, 5 ml. of dimethyl sulfide was added, and the cooling bath was removed. The temperature of the mixture rose to 32°, and then returned to ambient temperature after 1 hour of stirring. The solvent was then removed from the reaction mixture under vacuum at 35°, reducing the volume to about 15 ml. To the semi-solid was added 100 ml. of water, and the mixture was stirred for 15 minutes and filtered. The filter cake was washed with two 50 ml. portions of additional water, and the solids were dried under vacuum to obtain 8.06 g. of product, m.p. 173°-177°. It contained 0.1% water by Karl Fischer analysis, and its nuclear magnetic resonance spectrum, determined in CDCl3 on a 60 mHZ instrument, showed features at δ 6.60 (s, 1H); 5.82 (1H, X of ABX, JAX =7.8 Hz, JBX =2.2 Hz); 4.50 (bs, 1H, exchanges with D2O), 3.83-3.23 (2H, AB of ABX, JAB =3 Hz); 2.90 (s, 3H); 1.32 (s, 9H). Its infra-red spectrum (KBr pellet) showed bands at 3411 (m), 1699 (s), 1599 (m), 1517 (m), 1500 (m), 1479 (m), 1443 (m), 1402 (m) and 1277 (m) cm-1. A 5 g. sample of the above product was recrystallized from 25 ml. of boiling denatured ethanol to obtain 4.2 g. of purified product, m.p. 176°-179°. Its calculated elemental analysis was 55.22% C, 7.16% H, 17.56% N; the actual analysis was 55.49% C, 7.27% H, 17.28% N.

Provenance & Evidence