C(Cl)(=O)C([Cl:4])=O.[CH2:7]([O:9][C:10]([C:12]1[C:17](=[O:18])[N:16]([CH2:19][C:20]2[CH:25]=[CH:24][C:23]([O:26][CH3:27])=[CH:22][CH:21]=2)[C:15]2[CH:28]=[CH:29][S:30][C:14]=2[C:13]=1O)=[O:11])[CH3:8].CN(C=O)C>C(Cl)Cl>[CH2:7]([O:9][C:10]([C:12]1[C:17](=[O:18])[N:16]([CH2:19][C:20]2[CH:25]=[CH:24][C:23]([O:26][CH3:27])=[CH:22][CH:21]=2)[C:15]2[CH:28]=[CH:29][S:30][C:14]=2[C:13]=1[Cl:4])=[O:11])[CH3:8]Oxalyl chloride (4.8 mL, 55 mmol) was added to a solution of 7-hydroxy-4-(4-methoxybenzyl)-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester (54) (9.87 g, 27 mmol) in dry CH2Cl2 at 0° C. After adding anhydrous DMF (0.5 mL), the solution was allowed to come at room temperature and was further stirred at room temperature for 24 h. Excess solvent was evaporated to yield 7-chloro-4-(4-methoxybenzyl)-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester as off white solids. Yield 85%; 1H NMR (400 MHz, DMSO-d6) δ 1.30 (t, J=7.2 Hz, 3H), 3.70 (s, 3H), 5.36 (s, 2H), 6.88 (d, J=8.4 Hz, 2H), 7.24 (d, J=8.4 Hz, 2H), 7.53 (d, J=5.6 Hz, 1H), 8.20 (d, J=5.6 Hz, 1H ppm; MS m/z=378 amu (M++H).
Wird geladen…