反应详情

The compound 8-tert-butyl-1-oxa-2-azaspiro[4.5]dec-2-ene-3-carboxylic acid (120 mg, 0.51 mmol), 1-thiazol-2-ylpiperazine (110 mg, 0.51 mmol), 4-methylmorpholine (101 mg, 1.02 mmol) and O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (288 mg, 0.65 mmol) (HBTU) were dissolved in DMF (10 ml) and stirred overnight under a nitrogen atmosphere at RT. The solvent was removed under vacuum, the residue taken up in EtOAc and sat. aq. NaHCO3 solution and the phases were separated. The aqueous phase was extracted several times with EtOAc and the combined organic phases were washed with sat. aq. NaCl solution, dried over magnesium sulphate and the solvent was removed under vacuum. After purification by column chromatography (silica gel, hexane/EtOAc 3:1), the desired product (8-tert-butyl-1-oxa-2-azaspiro[4.5]dec-2-en-3-yl)-(4-thiazol-2-ylpiperazin-1-yl)methanone was obtained as a trans isomer (50 mg, 26% of the theoretical amount) and as a cis isomer (100 mg, 51% of the theoretical amount).

1. customThe solvent was removed under vacuum
2. customsat. aq. NaHCO3 solution and the phases were separated
3. extractionThe aqueous phase was extracted several times with EtOAc
4. washthe combined organic phases were washed with sat. aq. NaCl solution
5. dry with materialdried over magnesium sulphate
6. customthe solvent was removed under vacuum
7. customAfter purification by column chromatography (silica gel, hexane/EtOAc 3:1)