CS(C)=O.C(Cl)(C(Cl)=O)=O.[C:11]([O:15][C:16]([N:18]1[CH2:23][CH2:22][N:21]([CH:24]([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[CH2:25][OH:26])[CH2:20][CH2:19]1)=[O:17])([CH3:14])([CH3:13])[CH3:12]>C(Cl)Cl>[C:11]([O:15][C:16]([N:18]1[CH2:19][CH2:20][N:21]([CH:24]([C:27]2[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=2)[CH:25]=[O:26])[CH2:22][CH2:23]1)=[O:17])([CH3:14])([CH3:12])[CH3:13]To DMSO (2.19 mL) in MeCl2 (40 mL) at −78° C. was added (COCl)2 (1.29 mL, ×mmol) dropwise. The reaction mixture was allowed to stir at −78° C. for 15 minutes and then 4-(2-Hydroxy-1-phenyl-ethyl)piperazine-1-carboxylic acid tert-butyl ester (364) (3.78 g, 12.34 mmol) in MeCl2 (8 mL) was added. The reaction mixture was allowed to stir at −78° C. for 1 h and then TEA (8.6 mL) amine added. The reaction mixture was allowed to stir at −78° C. for another 3 h and then allowed to warm to room temperature and stirred for 18 h. The reaction mixture is then quenched with sat. NH4Cl (55 mL). The desired product is extracted into EtOAc (100 mL). The organic phase is dried over MgSO4 and concentrated to dryness. The crude material was purified by chromatography (silica gel 60 mesh, eluting with 30% EtOAc in hexanes) yielding 2.37 g (63%) pure product.
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