反应详情

4-Methoxy-3-nitrobenzoic acid (5.0 g, 25 mmol) was added to thionyl chloride (20 mL) under an inert atmosphere and stirred and heated to reflux. After 2 hours the mixture was stripped to dryness by rotary evaporator, and 2 portions of benzene were successively mixed with then stripped from the residue to leave a solid. This residue was dissolved in tetrahydrofuran (20 mL) and added dropwise to a stirred solution of methyl 3-aminobenzoate (3.83 g, 25 mmol) and pyridine (2 mL) cooled in an icebath. The mixture was allowed to warm to room temperature following the addition, then the solvent was removed under reduced pressure. The residue was suspended in 1N HCl, stirred, filtered off, and washed successively with 1N HCl, 1N NaHCO3 (2×), and water (2×). The resulting solid was boiled briefly in methanol (500 mL) then allowed to cool. Filtration afforded the product (8.0 g); m.p. 233-235° C., in sufficient purity for the next step.

1. temperatureheated to reflux
2. customAfter 2 hours the mixture was stripped to dryness by rotary evaporator, and 2 portions of benzene
3. additionwere successively mixed
4. customto leave a solid
5. temperaturecooled in an icebath
6. additionthe addition
7. customthe solvent was removed under reduced pressure
8. stirringstirred
9. filtrationfiltered off
10. washwashed successively with 1N HCl, 1N NaHCO3 (2×), and water (2×)
11. temperatureto cool
12. filtrationFiltration