反应详情

To above stirred mixture of methyl 6-chloro-2-methyl-3-nitrobenzoate 62 and methyl 6-chloro-2-methyl-5-nitrobenzoate in EtOH (500 mL), SnCl2.2H2O (224 g, 992 mmol, 4 eq) was added and the resulting mixture was stirred at reflux for 3 h. The reaction mixture was allowed to cool to RT and concentrated in vacuo. The residue was poured into water (1 L) and extracted with ethyl acetate (5×500 mL). The combined organic layers were washed with brine, dried over Na2SO4 and filtered. The filtrate was concentrated in vacuo and the residue was purified by flash column chromatography on silica gel (2-10% ethyl acetate-hexanes) to afford the regio-isomer methyl 3-amino-6-chloro-2-methylbenzoate 63.

1. additionwas added
2. stirringthe resulting mixture was stirred
3. temperatureat reflux for 3 h
4. concentrationconcentrated in vacuo
5. additionThe residue was poured into water (1 L)
6. extractionextracted with ethyl acetate (5×500 mL)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationThe filtrate was concentrated in vacuo
11. customthe residue was purified by flash column chromatography on silica gel (2-10% ethyl acetate-hexanes)