RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Absolute neutrophil count >= 1,000/mm^3 RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Hemoglobin >= 8 g/dl (may receive transfusions) RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Albumin >= 3 g/dl RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Potassium >= lower limit of normal (LLN) RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Serum total calcium (correct for serum albumin) or ionized calcium >= LLN RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients must agree to avoid grapefruit or grapefruit juice and Seville (sour) oranges during the entire study RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): The patient or parent/guardian is able to understand the consent and is willing to sign a written informed consent document according to institutional guidelines RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients who have had > 60 Gy total radiation to the pons (e.g. patients who have received re-irradiation) RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have had prior histone deacetylase (HDAC), deacetylase (DAC), heat shock protein 90 (HSP90) inhibitors for the treatment of their DIPG RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have had valproic acid within 28 days prior to enrollment RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have had prior bone marrow transplant RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have significant acute deterioration in neurologic status in 72 hours prior to enrollment, in the opinion of the treating physician RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have any other significant concurrent illness RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have a history of any other malignancy RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients are known to be refractory to red blood cell or platelet transfusions RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients who are receiving any other anticancer or investigational drug therapy RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients who are required to receive any medication which can prolong the QTc interval RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Female patient is breastfeeding NON-PROGRESSED DIPG (STRATUM 2): Patients with DIPG who have not yet progressed by clinical or radiographic criteria* Please note: patients with a radiographically typical DIPG, defined as a tumor with a pontine epicenter and diffuse involvement of more than 2/3 of the pons, are eligible without histologic confirmation* Patients with pontine lesions that do not meet these radiographic criteria will be eligible if there is histologic confirmation of malignant glioma World Health Organization (WHO) II-IV NON-PROGRESSED DIPG (STRATUM 2): Patients must have recovered from the acute treatment-related toxicities (defined as =< grade 1) of radiotherapy prior to entering this study NON-PROGRESSED DIPG (STRATUM 2): Absolute neutrophil count >= 1,000/mm^3 NON-PROGRESSED DIPG (STRATUM 2): Hemoglobin >= 8 g/dl (may receive transfusions) NON-PROGRESSED DIPG (STRATUM 2): ALT(SGPT) =< 3 x institutional upper limit of normal NON-PROGRESSED DIPG (STRATUM 2): Albumin >= 3 g/dl NON-PROGRESSED DIPG (STRATUM 2): Potassium >= LLN NON-PROGRESSED DIPG (STRATUM 2): Serum total calcium (correct for serum albumin) or ionized calcium >= LLN NON-PROGRESSED DIPG (STRATUM 2): Patient has no ventricular arrhythmias except for benign premature ventricular contractions NON-PROGRESSED DIPG (STRATUM 2): Patient has a QTc interval < 450 ms NON-PROGRESSED DIPG (STRATUM 2): Patients must agree to avoid grapefruit or grapefruit juice and Seville (sour) oranges during the entire study NON-PROGRESSED DIPG (STRATUM 2): The patient or parent/guardian is able to understand the consent and is willing to sign a written informed consent document according to institutional guidelines NON-PROGRESSED DIPG (STRATUM 2): Patients who have had > 60 Gy total radiation to the pons (e.g. patients who have received re-irradiation NON-PROGRESSED DIPG (STRATUM 2): Patients have significant acute deterioration in neurologic status in 72 hours prior to enrollment, in the opinion of the treating physician NON-PROGRESSED DIPG (STRATUM 2): Patients have diarrhea > CTCAE grade 2 NON-PROGRESSED DIPG (STRATUM 2): Patients have a history of any other malignancy NON-PROGRESSED DIPG (STRATUM 2): Patients are known to be refractory to red blood cell or platelet transfusions NON-PROGRESSED DIPG (STRATUM 2): Patients who are receiving any other anticancer or investigational drug therapy NON-PROGRESSED DIPG (STRATUM 2): Patients who are required to receive any medication which can prolong the QTc interval NON-PROGRESSED DIPG (STRATUM 2): Female patient is breastfeeding