No abstract

The mixed azines 3a-h and 4 were obtained by treating 3-hydrazonoindolin-2-one (2) with the appropriate aldehyde or dialdehyde. Treatment of 3b or 3c with formaldehyde or glutaric dialdehyde and the appropriate amine afforded the azine Mannich bases 5-7. The condensation of isatin or its N-Mannich base 8 with 1-aminopiperidine, 4-aminomorpholine and 1,4-diaminopiperazine gave 10a-d, 12 and 13. The Mannich bases 14 and 15 were obtained from 10a and 10b. Treatment of 2 with succinic, phthalic and quinolinic anhydride and pyromellitic dianhydride afforded compounds 16, 17a, 17b and 18, respectively. The synthesis of isatin Schiff bases incorporating a benzoylpiperidine, benzoylmorpholine and 1,4-dibezoylpiperazine moiety and their N-Mannich bases was investigated.

Pyrrolidine‐2,3‐diones are of continuing interest as intermediates in the synthesis of heterocycles related to pyrrolidine alkaloids, medicinally relevant compounds, and in the development of antibiotics and drugs. The present review deals with the most important literature on the synthesis and reactions of pyrrolidine‐2,3‐diones and the related biologically important compounds.

The hydrazide-hydrazones 6a–d and 7a, b were obtained by treating isatin (1) or its Mannich base 2 with hydrazides incorporating piperidine, morpholine, and piperazine units. The reaction of 1 and 2 with hydrazides related to triazenes having piperidine, morpholine, and 1,2,3,4-tetrahydroisoquinoline moieties gave 12a–c and 13a–c. Treatment of 1 and 2 with iminodiacetohydrazide (14) and ethylenediamine tetraacetohydrazide (18) afforded 15–17 and 19a, b, respectively. The Mannich reaction of the Schiff base 20 with formaldehyde and the appropriate hydrazide or bis(hydrazide) gave 21a, b and 22a, b. The hydrazides related to Schiff bases 20 and 26 were used as precursors in synthesis of compounds incorporating two 2-oxoindoline units or formazan moiety.

Treatment of isoindolin-1,3-dione (1) with formalin and the appropriate amine or diamine afforded new N-Mannich bases and bis-(Mannich bases) 2 to 6. The use of the appropriate hydrazide or dihydrazide as the amine component in the Mannich reaction with 1 led to Mannich bases and bis-(Mannich bases) incorporating a hydrazide moiety. The synthetic potential of sec-Mannich bases as precursors in synthesis of hybrid Mannich bases incorporating 1 was described.The N-alkylation of 1 with ketonic Mannich bases was investigated.