Potassium Carbonate → (R)-ethyl 2-(4-benzyl-2-oxoimidazolidin-1-yl)-4-methylthiazole-5-carboxylate

Participants

Reaction Steps

To a solution of (R)-ethyl 2-(3-(1-hydroxy-3-phenylpropan-2-yl)ureido)-4-methylthiazole-5-carboxylate (3.20 g, 8.80 mmol) and N,N-diisopropylethylamine (2.70 mL, 115.50 mmol) in tetrahydrofuran (50 mL) was added methanesulfonyl chloride (0.82 mL, 10.50 mmol) at 0° C. The reaction mixture was stirred at ambient temperature for 2 hours. To this reaction mixture was added potassium carbonate (1.38 g, 10.00 mmol), and heated to reflux for 17 hours. The solvent was removed in vacuo, the residue was dissolved in ethyl acetate (300 mL) and washed with water and brine. The organic solution was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and the residue was purified by column chromatography to afford the title compound in 47% yield (1.43 g): mp 102-103° C.; 1H NMR (300 MHz, acetone-d6) δ 9.38 (s, 1H), 7.37-7.23 (m, 5H), 4.60-4.17 (m, 5H), 3.07-2.95 (m, 2H), 2.44 (s, 3H) 1.26 (t, J=7.2 Hz, 3H); 13C NMR (75 MHz, acetone-d6) δ 174.9, 162.1, 161.7, 157.1, 136.9, 129.2, 128.7, 126.8, 113.0, 70.4, 60.1, 56.4, 40.3, 16.6, 13.7; MS (ES+) m/z 346.4 (M+1).

Provenance & Evidence