Thionyl Chloride → 3-methoxy-4-nitro-benzoyl Chloride
Reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[N+:12]([O-:14])=[O:13])[C:6](O)=[O:7].S(Cl)([Cl:17])=O>>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[N+:12]([O-:14])=[O:13])[C:6]([Cl:17])=[O:7]Participants
3
Procedure
A mixture of 5.0 g of 3-methoxy-4-nitrobenzoic acid and 5.0 g of thionyl chloride is heated under argon for 1 hour. The volatiles are removed in vacuo to give 2.85 g of a 3-methoxy-4-nitrobenzoyl chloride as a residue which is dissolved in 50 ml of methylene chloride. To the preceding solution is added with stirring 1.75 g of N,N-diisopropylethylamine followed by 1.84 g of 10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine. The reaction mixture is stirred under argon for 18 hours and diluted with saturated sodium bicarbonate. The organic layer is dried with Na2 SO4 and passed through a short pad of hydrous magnesium silicate. While boiling, hexane is added to the filtrate to give, upon cooling, 3.39 g of the desired product as a solid, m.p. 191°-192° C.