The reaction of Il2-diaminobenzene with heptane-2,4,6-trione yielded either the compound 2-(acetylmethyl) -4-methyl-3H-I ,5-benzodiazepine or 1 -(o-aminophenyl)-2,6-dimethyl-4-pyridone (5) depending upon the conditions used. The reaction of Il2-diaminobenzene with 1 -(0-hydroxyphenyl) -butane-I ,3-dione yielded a diazepine. In contrast the reaction of cis-I ,2-diaminocyclohexane with heptane-2,4,6-trione yielded a tetramine macrocyclic compound, and with 1 -(0-hydroxyphenyl) butane-I ,3-dione afforded the compartmental Schiff base 3,3'-(cis-1 ,2-cyclohexanediyldi-imino)bis[l -(o-hydroxyphenyl)but-2-enone] (1 0). The metal-complexing properties of this ligand are reported. Three-dimensional X-ray crystal-structure analyses have been carried out on compound (5) and on the mononuclear copper(ii) derivative of (lo), i.e. (12). Compound (5) has Z = 8 in a monoclinic cell with space group P2,/c, and dimensions a = 14.984(1), b = 7.475(3), c = 21.173(1) A, and P = 98.71JI)'; R = 0.0388 for 2 392 reflections. Complex (12) has Z = 4 in a triclinic cell with space group PI, and dimensions a = 13.143(8), b = 14.279(8), c = 14.289(14) A, a = 67.36(6), p = 71.18 (7), and y = 91.36(5)"; R = 0.0651 for 2 985 reflections. The structure shows the copper(ii) to occupy the inner (N202) co-ordination site in an environment with a marked (ca. 1 4') tetrahedral twist.The reaction of P-diketones with a,o-diamines leads to a large range of products depending on the experimental conditions used.2 In reaction (i) (Scheme) it is found that neutral and mildly alkaline media favour bis(oxoenamine) formation whereas reactions at pH < 6 and pH > 10 favour diazepine formation. In reaction (ii) (Scheme) it is the anil that is stabilised if R = R' = R2 = CH3 because of the steric hindrance of the vicinal methyl groups. With P-triketones extra degrees of complexity are offered and it has been found that reactions of heptane-2,4,6-trione with various stoicheiometric proportions of 1,2-diaminoethane (and also 1,2-and 1,3-diaminopropane) give the macrocyclic Schiff bases corresponding to (l).3 With the related unsymmetrical triketones, 1 -phenylhexane-1,3,5-trione and 7,7-dimethyloctane-2,4,6-trione, acyclic Schiff bases such as (2) are formed.4~~ These reactions parallel the behaviour of the corresponding P-diketones in which condensation occurs at the carbonyl group adjacent to the methyl The reaction of pentane-2,4-dione with 1,2-diaminobenzene has been shown to give the diazepine (3).* Using similar reaction conditions, 1,2-diaminobenzene in an ethanolethanoic acid mixture was treated with heptane-2,4,6-trione to give a red compound, subsequently identified as the diazepine (4). However if the reaction was carried out by adding the components in reverse order, followed by pouring into water and refrigerating, then two products were recovered, (4) together with a white crystalline compound identified as the pyridone (5).
