Dimethylformamide → N-[[[2-(chlorosulphonyl)-4-methoxyphenyl]amino]methylene]-N-methyl-methanaminium chloride

Participants

Reaction Conditions

Reaction Steps

Dimethylformamide (0.152 mol) is added dropwise to a suspension of 2-amino-5-methoxybenzenesulphonic acid (0.152 mol) in thionyl chloride (0.763 mol). The reaction mixture is heated very gradually to 70° C. and is maintained at that temperature for 1.5 hours. After cooling, the stirred reaction solution is treated by the addition of 20 ml of toluene. A precipitate is formed which is rapidly filtered off, rinsed with toluene and then dried at 40° C. in vacuo in the presence of KOH pellets, to yield the title product.

Provenance & Evidence