Reacción #1091

Ecuación de reacción

methanol

2-carboxy-5-nitrobenzenesulfonic acid

thionyl chloride

→

2-methoxycarbonyl-5-nitrobenzenesulfonic acid

Disolventes

DMF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturais heated
2. 2
   OtroAfter separating off the insoluble constituents
3. 3
   Filtraciónby filtration
4. 4
   Concentraciónthe filtrate is concentrated
5. 5
   Otroresults
6. 6
   workup.ADDITIONWhen addition
7. 7
   OtroThe solid which precipitates
8. 8
   Filtraciónis filtered off
9. 9
   Otrodried

Procedimiento

A suspension of 190.0 g (0.77 mol) of 2-carboxy-5-nitrobenzenesulfonic acid, 10 ml of DMF and 250 ml (3.43 mol) of thionyl chloride is heated at boiling for 3 h. After separating off the insoluble constituents by filtration, the filtrate is concentrated. 200 ml (4.94 mol) of methanol are added to the residue which results. When addition is complete the reaction mixture is cooled to 0° C. The solid which precipitates is filtered off and dried. 70.9 g (35.3% of theory) of colorless, crystalline 2-methoxycarbonyl-5-nitrobenzenesulfonic acid (m.p.: 92°-94° C.) are thus obtained. By distilling off the volatile components from the mother liquor, a second fraction (62.5 g, 31.1% of theory) is obtained.

Fuente