[CH3:1][O:2][C:3](=[O:29])[C@H:4]([CH2:21][C:22]1[CH:27]=[CH:26][C:25]([OH:28])=[CH:24][CH:23]=1)[NH:5][C:6]([C:8]1([NH:13]C(OC(C)(C)C)=O)[CH2:12][CH2:11][CH2:10][CH2:9]1)=[O:7].[ClH:30]>ClCCl.C(OCC)(=O)C>[ClH:30].[CH3:1][O:2][C:3](=[O:29])[C@H:4]([CH2:21][C:22]1[CH:23]=[CH:24][C:25]([OH:28])=[CH:26][CH:27]=1)[NH:5][C:6]([C:8]1([NH2:13])[CH2:12][CH2:11][CH2:10][CH2:9]1)=[O:7]To a solution of N-[[1-[[(1,1-dimethylethoxy)carbonyl]amino]-1-cyclopentyl]carbonyl]-L-tyrosine methyl ester (3.50 g, 8.6 mmol) in dichloromethane (60 mL) and ethyl acetate (10 mL) is bubbled dry HCl gas for 15 minutes. The solvent is then removed under reduced pressure to give, as a foam, [[1-amino(1-cyclopentyl)]carbonyl]-L-tyrosine methyl ester hydrochloride, the compound of formula III wherein R1 is 4-hydroxyphenyl, R2 is methyl, R3 is acetyl and R4 is isopropyl.
Wird geladen…