DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor

  • Advanced or metastatic disease
• Progressive disease during ≥ 1 prior standard therapy OR disease unlikely to respond to any currently available therapies
• Measurable or evaluable disease

• No known active CNS metastases

  • Patients with previously treated CNS metastases who have no evidence of new CNS metastases AND are stable for ≥ 2 months are eligible

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Life expectancy > 3 months
• Platelet count ≥ 100,000/mm^3
• Hemoglobin ≥ 10 g/dL (transfusions allowed)
• Absolute neutrophil count ≥ 1,500/mm^3
• ALT and AST ≤ 2.5 times upper limit of normal (ULN)
• Alkaline phosphatase ≤ 2.5 times ULN
• Creatinine ≤ 1.5 mg/dL OR creatinine clearance ≥ 50 mL/min
• Bilirubin normal
• PT/PTT ≤ 1.5 times ULN
• FEV_1 ≥ 1.2 L
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception 2 weeks prior to and during study treatment
• Must be able to swallow
• No mental deficits and/or psychiatric history that may preclude study treatment

• No active heart disease, including any of the following:

  • Myocardial infarction within the past 3 months
  • Symptomatic coronary artery disease or heart block
  • Uncontrolled congestive heart failure
• No moderate to severe compromise of pulmonary function
• No active infection
• No other life-threatening illness
• No active coagulation disorder other than occult blood
• No known positivity for glucose-6-phosphate dehydrogenase (G6PD) deficiency

PRIOR CONCURRENT THERAPY:

• Recovered from prior treatment
• Prior gemcitabine allowed
• More than 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
• More than 3 weeks since prior radiotherapy or any other treatment for this cancer
• No prior 3-AP
• No concurrent radiotherapy
• No other concurrent investigational agent