N-substituted hydrazines were described. Hydrazones (6, 7a, 8a–c, 9b–e, 10e, 11e, 12) were evaluated for cytotoxicity (MTT test) against HL-60 and NALM-6 leukemia cells. Phosphorohydrazone of 3-formylchromone 8a and hydrazone of 2-amino-3-chromone derivative 11e showed appreciable cytotoxicity. The cytotoxicity indices of 8a, 11e, and 12 were higher on drug-resistant HL-60 ADR cells in comparison to