Synthesis of 2-Acetoacetyl- and 2-Oxaloacetyl-l,3-indandiones and Related Compounds

Claisen condensation of 2-acetyl-l,3-indandione (1) with ethyl acetate afforded the 2-acetoacetyl-l,3-indandione (2) which upon treatment with benzylamine and paraformaldehyde in a molar ratio of (1:1:2) and (1:2:4) afforded the piperidinone and the diazabicyclic derivative (4)and (5) respectively. On the other hand, Claisen condensation of 1 with diethyl oxalate yielded two products (6) and (9). The behaviour of 6 towards phenyl hydrazine, and of 9 towards selenium dioxide and double Mannich reaction were also investigated.