反应详情

A solution of the crude tert-butyl 4-(2-chloroacetyl)piperidine-1-carboxylate (one third the material from step 1, approximately 5 mmol) in DMSO (20 mL) was charged with 1-(5-chloro-2-hydroxyphenyl)urea (see N. Hossain et al., WO PCT 2004/005295; 980 mg, 5.25 mmol) and K2CO3 (1.38 g, 10 mmol). The reaction was stirred for ˜14 h and then quenched with water (40 mL). The mixture was extracted twice with EtOAc. The organic phases were combined, washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. The resultant residue was purified by flash chromatography to afford tert-butyl 4-(2-(4-chloro-2-ureidophenoxy)acetyl)piperidine-1-carboxylate (550 mg, ˜25% yield) as a solid. LC/MS [M-Boc]+=312.3, [M+Na]+=434.3.

1. customquenched with water (40 mL)
2. extractionThe mixture was extracted twice with EtOAc
3. washwashed with brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe resultant residue was purified by flash chromatography