Hydrochloric Acid → (+)-(4R)-4-(3-nitrobenzyl)-4,5-dihydro-1,3-thiazol-2-ylamine hydrochloride

Participants

Reaction Conditions

Reaction Steps

1.1 g of N-(tert-butyl)-N′-[(1R)-2-hydroxy-1-(3-nitrobenzyl)ethyl]thiourea in 12 cm3 of 6N hydrochloric acid are heated for 5 hours at a temperature in the region of 100° C. The reaction medium is then cooled to a temperature in the region of 0° C.; a white precipitate forms, which is filtered off on a sinter funnel and then washed with 3 times 20 cm3 of diethyl ether. The filter cake is then dried in a desiccator under vacuum. 0.68 g of (+)-(4R)-4-(3-nitrobenzyl)-4,5-dihydro-1,3-thiazol-2-ylamine hydrochloride is obtained in the form of beige-colored crystals melting at 232° C. [1H NMR spectrum (300 MHz, (CD3)2SO-d6, δ in ppm): 3.15 (limiting AB: 2H); from 3.25 to 3.45 (mt: 1H); 3.63 (dd, J=13 and 8 Hz: 1H); 4.62 (mt: 1H); 7.68 (t, J=8 Hz: 1H); 7.81 (broad d, J=8 Hz: 1H); 8.18 (broad d, J=8 Hz: 1H); 8.24 (broad s: 1H); from 9.00 to 10.40 (unres. mult.: 3H); (αD20=+18.8±0.6 at a concentration of 0.5% in methanol)].

Provenance & Evidence