Acid-catalysed, '3+3' condensation of m-bispyrryl benzene derivatives with acetone afforded new non-aromatic macrocycles that can be converted to meso-alkylidenyl dibenzohexaphyrins carrying four exocyclic double bonds at meso-positions by DDQ oxidation.

In the title compound, C20H22N5O(+)·Br(-)·C2H6O, the tetra-hydro-pyrimidine ring of the bicyclic cation adopts a half-chair conformation with an equatorial orientation of the phenyl and methyl substituents. The amino group is nearly coplanar with the 1,2,4-triazole ring [interplanar angle = 4.08 (8)°] and has a slightly pyramidal configuration. The mean planes of the triazole ring and the benze...

The title compound, C(14)H(16)N(2)O(3), is an NH-vinyl-ogous amide (enaminone) produced by the reaction of 4-nitro-phenacyl bromide with azepane-2-thione. The conformation about the C=C bond [1.3927 (14) Å] is Z, which allows for the formation of an intra-molecular N-H⋯O hydrogen bond that leads to an S(6) loop. Inversion-related mol-ecules associate via N-H⋯O hydrogen bonds to form a 12-member...

Ring cleavage occurred when 1,2,4-triazino-1,2,4-triazines (3), (4) and (5) were treated with concentrated hydrochloric acid to yield N-substituted triazines (7) and (8). These confirm the given configuration assigned to the isomeric triazinotriazines. 6-Methyl-2-phenyl-7H-oxazolo [3,2-b][1,2,4]-triazin-7-one (9) underwent ring cleavage on treatment with sodium alkoxide to afford 3-alkoxy-1...