反应详情

2,6-Dichloro-4-trifluoromethylphenylaniline (4.3 g) was dissolved with stirring, in glacial acetic acid (23 ml). A solution of sodium nitrite (1.5 g) in concentrated sulphuric acid (11 ml) was then added at 55°-60° C. The solution thus obtained was cooled to 0°-5° C. and a solution of stannous chloride (16.4 g) in concentrated hydrochloric acid (14 ml) was added with vigorous stirring. A cream-colored solid precipitated. The mixture was filtered and the solid obtained was added to a mixture of aqueous ammonia solution and ice. The mixture thus obtained was extracted with diethyl ether (6×500 ml) and the combined ethereal extracts were dried over sodium sulphate, filtered and evaporated to dryness to give 2,6-dichloro-4-trifluoromethylphenylhydrazine (3.7 g) m.p. 54°-56° C., in the form of a colorless crystalline solid.

1. customThe solution thus obtained
2. temperaturewas cooled to 0°-5° C.
3. customA cream-colored solid precipitated
4. filtrationThe mixture was filtered
5. customthe solid obtained
6. customThe mixture thus obtained
7. extractionwas extracted with diethyl ether (6×500 ml)
8. dry with materialthe combined ethereal extracts were dried over sodium sulphate
9. filtrationfiltered
10. customevaporated to dryness