Dehydrohalogenation collidine

The fully unsaturated tricyclic compounds are also used clinically as antidepressants. Carbamazepine (62), for example, is prepared from 10,ll-dihydro-5H-dibenz[b,f]azepine (49) by N-acetylation followed by bromination with W-bromosuccinimide to give 60. Dehydrohalogenation by heating in collidine introduces the double bond. Saponification with potassium hydroxide in ethanol leads to dibenz[b,f]azepine (61), the parent substance for the fully unsaturated analogs. Treatment of the secondary... 

Plieninger et al. found the method advantageous for conversion of the enone (12) into the dienone (15). The yield in the dehydrohalogenation of (14) was over twice that obtained with collidine (40%). 

The case of 2-chloro-2-methylcyclohexanone (2) presents no comparable steric difficulty, and here dehydrohalogenation by the Holysz method and with collidine both proceed rather poorly and in comparable yield. ... 

Found in low-temp, coal tar and coal soot. Catalyst. Forms complexes. Base for dehydrohalogenations. Used in extraction, separation of Zr and Sc as ternary complexes with salicylic acid and collidine (CHCI3). Liq. Sol. acids, CHCI3. d 0.917. Mp 42°. Bp 175-178°. pA , 6.69 (25°). 

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