[S:1]1[C:5]2[C:6]([C:10]([OH:12])=O)=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[N:2]1.CN(C)C=O.S(Cl)([Cl:20])=O>C1(C)C=CC=CC=1>[S:1]1[C:5]2[C:6]([C:10]([Cl:20])=[O:12])=[CH:7][CH:8]=[CH:9][C:4]=2[N:3]=[N:2]1290 g of benzo-1,2,3-thiadiazole-7-carboxylic acid are suspended in 1.6 l of toluene, 3.5 ml of dimethylformamide and 129 ml of thionyl chloride are added and the mixture is stirred at 80-90° C., the suspension turning into a solution as the release of gas progresses. When the reaction has ended, the solution is cooled and filtered over a little Hyflo, the residue is rinsed with toluene and the filtrate is evaporated. 297 g (93%) of crude acid chloride, which can be further reacted directly, result.
Wird geladen…