[Na].[CH:2]1([CH2:5][O:6][CH2:7][C:8](=O)[CH2:9][C:10]([O:12]CC)=O)[CH2:4][CH2:3]1.[NH2:16][C:17]([NH2:19])=[S:18].Cl>CCO>[CH:2]1([CH2:5][O:6][CH2:7][C:8]2[NH:19][C:17](=[S:18])[NH:16][C:10](=[O:12])[CH:9]=2)[CH2:4][CH2:3]1Sodium (4.0 g, 172 mmol) was added to EtOH (80 mL) and stirred until all dissolved at 60° C. The solution was cooled down to rt and a solution of ethyl 4-(cyclopropylmethoxy)-3-oxobutanoate (15.7 g, 78.4 mmol) in EtOH (80 mL) was added, followed by thiourea (7.2 g, 94 mmol). The mixture was stirred under reflux conditions for 24 h. Hydrochloric acid (aq, 1 M) was added until pH˜4 and the mixture was concentrated in vacuo. The residue was purified by column chromatography on silica eluting with a gradient of EtOAc and DCM to give the title compound as a solid, 15.7 g (95%).
Loading…
