1.4- Diazocin-5 -ones 1,2,3,4-tetrahydro

One of the earliest authentic eight-membered heterocyclic compounds to be described was 6,7-diphenyldibenzo[e,g][l,4]diazocine (212) prepared by Tauber in 1892 by condensation of 2,2 -diaminobiphenyl and benzil. The diazocine ring is opened hydrolytically under vigorous conditions and is reduced to the 5,6,7,8-tetrahydro compound with sodium amal-... 

In some respects, the nomenclature of 1,4-diazocines is similar to that for the eight-membered ring containing one nitrogen (82AHC115). The completely unsaturated compound, for which there exists two valence tautomeric structures, 5 and 6, is called 1,4-diazocine. The partially saturated derivatives are prefixed dihydro-, tetrahydro-, etc. The totally saturated compound is called perhydro-1,4-diazocine, or 1,4-diazacyclooctane. 

Troger s base [I (Fig. 1). R=CR3, X=-H] (5,6,11,12-tetrahydro 2,8-dimethyl-5,1 1 -methanodibenzo [b,f][l,5]diazocine) was first obtained from p-toluidine, formaldehyde, and acid in 1887. The yields are not very high in that procedure but may reach 70% under carefully selected conditions.Numerous derivatives, including double Troger s bases, were prepared by this one-pot approach, however, only p-substituted aniline derivatives were successful.The unsubstituted system nor-Troger s... 

---