反应详情

1.0 g of 3,4-dihydroxy-5-nitrobenzoic acid is treated with 20 ml of methanolic hydrochloric acid, stirred at 45° for 3 hours and, after removing the solvent, the residue is taken up in methylene chloride. The organic phase is washed with sodium chloride solution, dried over sodium sulfate and evaporated. The crystalline product obtained is taken up in methylene chloride and filtered over a ten-fold amount of silica gel. The material obtained is recrystallized from ethyl acetate/n-hexane. There is obtained methyl 3,4-dihydroxy-5-nitrobenzoate in the form of yellow crystals of m.p. 144°-145°.

1. customafter removing the solvent
2. washThe organic phase is washed with sodium chloride solution
3. dry with materialdried over sodium sulfate
4. customevaporated
5. customThe crystalline product obtained
6. filtrationfiltered over a ten-fold amount of silica gel
7. customThe material obtained
8. customis recrystallized from ethyl acetate/n-hexane