[OH:1][C:2]1[C:3]([O:14][CH3:15])=[CH:4][C:5]2[CH:9]=[C:8]([C:10]([OH:12])=[O:11])[S:7][C:6]=2[CH:13]=1.[N+:16]([O-])([OH:18])=[O:17]>C(OCC)(=O)C.ClCCl>[OH:1][C:2]1[C:3]([O:14][CH3:15])=[CH:4][C:5]2[CH:9]=[C:8]([C:10]([OH:12])=[O:11])[S:7][C:6]=2[C:13]=1[N+:16]([O-:18])=[O:17]6-Hydroxy-5-methoxy-benzo[b]thiophene-2-carboxylic acid (3.2 g) was dissolved in ethyl acetate (200 ml) and a solution of nitric acid in dichloromethane (2M, 7.7 ml) was gradually added at 0° C. into. The solution was stirred 30 min at room temperature and then it was poured into ice-cold water and filtered. The solid was washed with ethyl acetate and dried under vacuum.
Wird geladen…