ELECTROCHEMICAL REDUCTION OF 5H-DIBENZ[B,F]AZEPINE DERIVATIVES .7. CATHODIC DEHALOGENATION REACTIONS OF 10-BROMO-5H-DIBENZ[B,F]AZEPINES, 10,11-DIBROMO-5H-DIBENZ[B,F]AZEPINES AND 10,11-DIBROMO-10,11-DIHYDRO-5H-DIBENZ[B,F]AZEPINES - SYNTHESIS OF 10-CYCLOALKYLAMINO-5H-DIBENZ[B,F]AZEPINES

The dcp and cv investigations of 10-bromo-5 H-dibenz[b, f]azepines 1 in aprotic medium [0.1 mol/l (C2H5)4NClO4/dimethyl formamide], the interpretation of the mechanism of the cathodic debromination and the application of the debromination reactions to preparative electrolysis have been extended to vicinal dibromides as 10,11-dibromo-5 H-dibenz[b, f]azepines 3 or 4 and 10,11-dibromo-10,11-dihydro-5 H-dibenz[b, f]azepines 5 or 6. The bromo compounds 1 can be converted into the appropriate 5 H-dibenz[b, f]azepines, the bromo compounds 5 and 6 on cathodic reduction undergo the formation of the 10,11-C,C double bond. The electrochemical debromination of 3 or 4 gives the reactive intermediates 10,11-dehydro-5 H-dibenz[b, f]azepines 11, which have been trapped to 10-cycloalkylamino-5 H-dibenz[b, f]azepines 12. An alternative synthetic sequence starting from 10-bromo-5-carbamoyl-5 H-dibenz-[b, f]azepine has been used for the preparation of 12.