反应详情

温度

150 °C

A mixture of t-butyl 2-nitro-3,5,6-trichlorophenylacetate (from step (a), 123 g, 0.361 mol), and saturated aqueous ammonia (300ml) in 2-methoxy ethanol (360 ml) was heated in an autoclave at 150° C. for 72 h. The resulting viscous, black mixture was diluted with water (1 L) and ethyl acetate (1 L) and filtered through Arbocel filter aid. The dark red filtrate was separated, and the aqueous layer extracted with ethyl acetate (2×1 L). The combined organic solutions were washed with brine (1 L), dried (MgSO4) and evaporated onto silica gel (70-200 m, 200 g). The silica gel was applied to the top of the chromatography column containing silica gel (40-60 m, 800 g). Elution with hexane/ethyl acetate (98:2-92:8) gave 3-amino-5,6-dichloro-2-nitrotoluene (Eur. Pat. 385,850) as a bright orange solid (39.7 g), which was contaminated with 5-amino-3,6-dichloro-2-nitrotoluene (14%). This mixture was carried onto the next step without further purification.

1. filtrationfiltered through Arbocel
2. filtrationfilter aid
3. customThe dark red filtrate was separated
4. extractionthe aqueous layer extracted with ethyl acetate (2×1 L)
5. washThe combined organic solutions were washed with brine (1 L)
6. dry with materialdried (MgSO4)
7. customevaporated onto silica gel (70-200 m, 200 g)
8. additioncontaining silica gel (40-60 m, 800 g)
9. washElution with hexane/ethyl acetate (98:2-92:8)