反应详情

To a suspension of Ethyl 2-(3-(3,4-dichlorobenzyl)ureido)thiazole-4-carboxylate Example 38 (172 mg, 460 μmol) in THF (8 ml) was added a solution of lithium boronate/THF (1 M, 0.7 ml, 700 μmol) at 0° C. Stirring was continued at 0° C. for 2 hours. After this time, TLC indicated complete conversion and to the reaction mixture was added sodium sulfate decahydrate (1.20 g, 3.72 mmol). While warming up to ambient temperature, the mixture was stirred for further 20 minutes. The solids were removed by filtration and the solvent was removed under reduced pressure. The crude material was purified by column chromatography (silica gel, ethyl acetate, methanol/ethyl acetate 1:40, 1:30, 1:20, 1:15), yielding the desired compound in 75% (115 mg, 346 μmol) as a white solid. 1H NMR (300 MHz, d6-DMSO) δ 4.32 (d, 2H), 4.37 (d, 2H), 5.10 (t, br, 1H), 6.71 (s, 1H), 7.18 (t, br, 1H), 7.27 (dd, 1H), 7.51 (d, 1H), 7.59 (d, 1H), 10.53 (s, br, 1H). MS (ES+): M/Z 332 and 334 (M+H).

1. stirringthe mixture was stirred for further 20 minutes
2. customThe solids were removed by filtration
3. customthe solvent was removed under reduced pressure
4. customThe crude material was purified by column chromatography (silica gel, ethyl acetate, methanol/ethyl acetate 1:40, 1:30, 1:20, 1:15)