VNP40101M in Treating Patients With Relapsed or Refractory Leukemia or Myelodysplastic Syndrome

DISEASE CHARACTERISTICS: * Relapsed or refractory leukemia for which no standard therapy is anticipated to result in a durable remission OR * Poor-risk myelodysplastic syndromes PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-1 Life expectancy * Not specified Hematopoietic * Not specified Hepatic * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * AST and ALT no greater than 3 times ULN Renal * Creatinine no greater than 2.0 mg/dL Cardiovascular * No myocardial infarction within the past 3 months * No symptomatic coronary artery disease * No uncontrolled arrhythmia * No uncontrolled congestive heart failure Other * No uncontrolled active infection PRIOR CONCURRENT THERAPY: Biologic therapy * Prior biologic therapy allowed Chemotherapy * At least 2 weeks since prior myelosuppressive cytotoxic chemotherapy in the absence of rapidly progressing disease * At least 48 hours since prior hydroxyurea Endocrine therapy * Not specified Radiotherapy * Prior radiotherapy allowed Surgery * Not specified Other * No other concurrent standard or investigational treatment for leukemia * No concurrent disulfiram