Chloromethyl ethyl ketone → tert-butyl (1R,3R,4S)-4-((benzyloxycarbonyl)amino)-3-(4-ethylthiazol-2-yl)cyclohexylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl (1R,3R,4S)-4-((benzyloxycarbonyl)amino)-3-carbamothioylcyclohexylcarbamate (0.5 g, 0.0012 mol, see Example 12f, Step 2) in dry benzene (20 ml) under nitrogen was added 1-chloro-butan-2-one (0.42 g, 0.0039 mol) of and the reaction mixture was heated at 75° C. for over night. Benzene was removed under vaccum and the crude product was extracted with ethyl acetate. The organic layer was washed with brine, concentrated, and purified by recrystallization from ether to give 0.2 g (35%) of tert-butyl (1R,3R,4S)-4-((benzyloxycarbonyl)amino)-3-(4-ethylthiazol-2-yl)cyclohexylcarbamate as a white solid obtained. 1H NMR (400 MHz, CDCl3) δ 1.27 (t, 3H), 1.44 (s, 9H), 1.62 (m, 2H), 1.81 (m, 3 H), 2.22 (m, 2H), 2.78 (q, 2H), 3.50 (bs, 1H), 3.72 (bs, 1H), 4.12 (bs, 1H), 5.04 (s, 2H), 5.40 (bs, 1H), 5.74 (s, 1H), 7.33 (m, 5H); 13H NMR (400 MHz, CDCl3) 13.45, 24.7, 28.0, 28.24, 28.4, 33.3, 42.3, 47.0, 50.4, 61.0, 66.5, 79.0, 111.6, 127.9, 128.0, 128.4, 136.5, 155.2, 155.8, 158.8, 169.8. MS found: (M+H)+=460.

Provenance & Evidence