Phosphorus oxychloride → N-(3,4-dichlorostyrylsulfonyl)-3,4-dimethoxybenzamide

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4]([CH:11]=[CH:12][C:13]=1[Cl:14])[CH:5]=[CH:6][S:7]([NH2:10])(=[O:9])=[O:8].[CH3:15][O:16][C:17]1[CH:18]=[C:19]([CH:23]=[CH:24][C:25]=1[O:26][CH3:27])[C:20](Cl)=[O:21].P(Cl)(Cl)(Cl)=O>>[Cl:1][C:2]1[CH:3]=[C:4]([CH:11]=[CH:12][C:13]=1[Cl:14])[CH:5]=[CH:6][S:7]([NH:10][C:20](=[O:21])[C:19]1[CH:23]=[CH:24][C:25]([O:26][CH3:27])=[C:17]([O:16][CH3:15])[CH:18]=1)(=[O:8])=[O:9]

Participants

Reactant 3

HCID 24813Phosphorus oxychloride

HCID 77070Veratroyl chloride

HCID 537943803,4-Dichlorostyrylsulfonamide

Product 1

HCID 54226549N-(3,4-dichlorostyrylsulfonyl)-3,4-dimethoxybenzamideYield 70%

Procedure

A mixture of 3,4-dichlorostyrylsulfonamide (12.6 g., 0.05 mole) and 3,4-dimethoxybenzoyl chloride (11.0 g., 0.055 mole) in 15 ml. of phosphorus oxychloride is heated at steam bath temperature for a period of 30 min. Excess phosphorus oxychloride is removed under reduced pressure and dry benzene added. The benzene is evaporated and the treatment repeated two times. Benzene (50 ml.) is added to the residue thus obtained and the insoluble solid collected providing 14.6 g. (70% yield) of N-(3,4-dichlorostyrylsulfonyl)-3,4-dimethoxybenzamide, m.p. 145°-147° C.