Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of 1 of the following hematologic malignancies:

- Fludarabine refractory or relapsed chronic lymphocytic leukemia (CLL)

- CLL in transformation allowed

- Richter syndrome

- Other refractory lymphoproliferative diseases

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- Creatinine ≤ 2.0 mg/dL

- Renal dysfunction due to organ infiltration by disease allowed

- AST and ALT ≤ 3 times upper limit of normal (ULN) (unless due to organ infiltration
by disease)

- Bilirubin ≤ 1.5 times ULN (unless due to Gilbert's syndrome)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No uncontrolled infection

- No symptomatic coronary artery disease

- No arrhythmia not controlled by medication

- No uncontrolled, symptomatic congestive heart failure

- No myocardial infarction within the past 3 months

- No other uncontrolled illness

- No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

- At least 2 weeks since prior cytotoxic therapy except in patients with rapidly
progressing disease

- No other concurrent standard or investigational treatment for this cancer

- No other concurrent cytotoxic investigational drugs

- No concurrent disulfiram