Eight-membered Rings containing Two Heteroatoms

Structxxre (389) has been obtained by treatment of the corresponding an-thranilic acid with toluene-/7-sulphonyl chloride in pyridine. The preparation of l,2-diazacyclo-octa-2,4,6,8-tetraene (390) has been descried previously, and other workers now report the termination of unsuccessful 

The first report of medium-sized cyclic azo-compounds containing /m/M-azo-linkages has appeared. rra 5-l,2-Diazacyclo-oct-l-ene, trans-3,8-dimethyl-fra j-l, 2-diazacyclo-oct-l-ene, trans-, 2-diazacyclonon-l-ene, and trans-l, 2-diazacyclodec-l-ene have been prepared, the first by irradiation of the c -isomer and the remainder by cyclization-oxidation techniques, and their stereochemistries established Ijy n.m.r., u.v., and dipole moment measurements. 

Bolotin, M. V. Loseva, and I. P. Shepilov, Trudy Vses. Nauch. Issted. Inst. Khim. 

Reaktiv. Osobo Chist. Khim. Veshchestiv, 1971,33,104(CAem. Abs., 1972,77,164 616w). 

Two papers deal with the chemistry of 1,4-dioxocin (416), reported for the first time and prepared by the route shown. The equilibrium (416) (417) is observable above 50 °C at 60 °C in benzene the relative amounts are 95 5, respectively. 

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