2-Methanesulfonylphenol → 3-cyclopentyl-2-[4-(2-methanesulfonyl-phenoxy)-6-oxo-6H-pyridazin-1-yl]-propionic acid
Reaction equation
Cl[C:2]1[C:3](=[O:15])[N:4](C2CCCCO2)[N:5]=[CH:6][C:7]=1Cl.[CH3:16][S:17]([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][C:21]=1[OH:26])(=[O:19])=[O:18].C[O:28][C:29](=[O:38])[CH:30](Br)[CH2:31][CH:32]1[CH2:36][CH2:35][CH2:34][CH2:33]1>>[CH:32]1([CH2:31][CH:30]([N:4]2[C:3](=[O:15])[CH:2]=[C:7]([O:26][C:21]3[CH:22]=[CH:23][CH:24]=[CH:25][C:20]=3[S:17]([CH3:16])(=[O:18])=[O:19])[CH:6]=[N:5]2)[C:29]([OH:28])=[O:38])[CH2:36][CH2:35][CH2:34][CH2:33]1Participants
4
Procedure
In an analogous manner to the stepwise sequence outlined in intermediate 19, starting from 4,5-dichloro-2-(tetrahydropyran-2-yl)-2H-pyridazin-3-one (Intermediate 20) and 2-methanesulfonyl-phenol and alkylating with 2-bromo-3-cyclopentyl-propionic acid methyl ester (Intermediate 10) afforded 3-cyclopentyl-2-[4-(2-methanesulfonyl-phenoxy)-6-oxo-6H-pyridazin-1-yl]-propionic acid (15 g, 68%) as a white solid; LC-MS: [M+H+]=407; HPLC (0.17% trifluoroacetic acid in acetonitrile/water, 50%-100% acetonitrile, gradient, 1 mL/min, Venusil MP-C18, C18-15 cm×4.6 mm-5 μm), purity 98%. 1H-NMR (300 MHz, DMSO-d6) δ 1.42 (m, 2H), 1.55 (m, 7H), 1.57 (s, 1H), 1.59 (s, 1H), 3.31 (s, 1H), 5.31 (m, 1H), 7.63 (m, 1H), 7.87 (s, 2H), 7.98 (m, 1H), 8.19 (s, 1H).