反应详情

A mixture of 1.3 g of crude 2-chloro-4-nitro-4-(4-hydroxyphenyl)azobenzene, 20 ml of ethanol, 0.658 g of 1-bromoheptane, 0.528 g of potassium carbonate and a spatula tip of sodium iodide was boiled at reflux while stirring for 22 hours. The brown suspension was subsequently concentrated in vacuo and the residue was chromatographed on silica gel with toluene/hexane as the eluent. Recrystallization from methylene chloride/hexane, yielded 0.863 g of 2-chloro-4-nitro-4'-(4-heptyloxyphenyl)-azobenzene as orange crystals; m.p. (C-N) 83.1°-83.7° C., cl.p. (N-I) 179.4°-179.8° C.; E300 =11580, E406 =25910.

1. temperatureat reflux
2. concentrationThe brown suspension was subsequently concentrated in vacuo
3. customthe residue was chromatographed on silica gel with toluene/hexane as the eluent
4. customRecrystallization from methylene chloride/hexane