Efatutazone Dihydrochloride in Treating Patients With Previously Treated Myxoid Liposarcoma That Cannot Be Removed by Surgery

* Patients must have a formalin-fixed, paraffin-embedded (FFPE) tumor block OR 1 representative hematoxylin and eosin (H\&E) and 20 unstained myxoid liposarcoma tissue slides available for submission to central pathology review; this review is mandatory prior to registration to confirm eligibility * Measurable disease * Progression on at least one prior systemic chemotherapy for advanced, unresectable or metastatic disease; prior adjuvant or neoadjuvant therapy is not included as prior systemic chemotherapy unless treatment occurred within the 6 months prior to study enrollment * There is no limit to the number of prior lines of treatment a patient has received * No treatment with biologic therapy, immunotherapy, chemotherapy, investigational agent for malignancy, or radiation =\< 28 days before study registration; no treatment with nitrosourea or mitomycin =\< 42 days before study registration * Patients should have resolution of any toxic effects of prior therapy (except alopecia) to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, grade 1 or less * No history of the following: * Class III or IV congestive heart failure (CHF) * Pericardial effusion =\< 12 months (grade 3 or 4) * Pericardial involvement with tumor * Grade 2 or higher pleural effusion =\< 6 months * No symptomatic, untreated, or uncontrolled brain metastases present * Not pregnant and not nursing; for women of childbearing potential only, a n…