The chemistry of some fused eight-membered heterocyclic systems

It has been attempted in this thesis to compile information available in the literature on the synthesis of some eight-membered heterocyclic ring systems fused with one or two benzene rings (benzo- and dibenzo- respectively), having one nitrogen (azocines), two nitrogens (diazocines), and one nitrogen and one oxygen (oxazocines) in the ring system. Literature up to the end of 1978 has been covered. While this work was in progress, a similar report appeared in Rodd's Chemistry of Carbon Compounds, Volume IV -K. 1 This review article covers the literature up to the end of 1972 only and does not include oxazocines. With the growing interest in the pharmacological activity of medium rings, synthetic work in this area has seen a remarkable increase during the 1970's. Figures 1 and 2 show the distribution of publications during the period covered in this thesis, and it is evident that a large amount of work has been carried out after 1972. Synthetic work on dibenzodiazocines has been reported from the early 1880's, but only six publications appeared up to the end of 1920. Relative positions of the hetero atoms and the ring fusion give rise to a number of structural isomers in each benzo- and dibenzosystem. The number of possible isomers and the number of isomers reported (to the end of 1978) in each case is given in Table 1. All the structural isomers of benz- and dibenzazocines are known, whereas those ring systems containing nitrogen and . oxygen, oxazocines, are less well known and should provide a fertile area for future synthetic endeavours.