反应详情

2,6-Dichloro-4-trifluoromethylphenylaniline (4.3 g) (described in U.S. Pat. No. 3,850,955) 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-coloured 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 (×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 colourless crystalline solid.

1. dissolution3,850,955) was dissolved
2. customThe solution thus obtained
3. temperaturewas cooled to 0°-5° C.
4. customA cream-coloured solid precipitated
5. filtrationThe mixture was filtered
6. customthe solid obtained
7. customThe mixture thus obtained
8. extractionwas extracted with diethyl ether (×500 ml)
9. dry with materialthe combined ethereal extracts were dried over sodium sulphate
10. filtrationfiltered
11. customevaporated to dryness