Neuroprotective bicyclic compounds and methods for their use in treating autism spectrum disorders and neurodevelopmental disorders

A method for treating a symptom of an Autism Spectrum Disorder (ASD) or Neurodevelopmental Disorder (NDD) selected from the group consisting of Asperger Syndrome, Childhood Disintegrative Disorder and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS), Pathological Demand Avoidance (PDA), Fragile X Syndrome (FXS), Angelman Syndrome, Tuberous Sclerosis Complex, Phelan McDermid Syndrome, Rett Syndrome, CDKL5 mutations, and X-Linked Infantile Spasm Disorder in a mammal suffering from such a disorder, comprising administering to the mammal, a compound having the formula:

• or a pharmaceutically acceptable salt or hydrate thereof, wherein
• X1 is selected from the group consisting of NR′, O and S;
• X2 is selected from the group consisting of CH2, NR′, O and S;
• R1, R2, R3, R4 and R5 are independently selected from the group consisting of —H, —OR′, —SR′, —NR′R′, —NO2, —CN, —C(O)R′, —C(O)OR′, —C(O)NR′R′, —C(NR′)NR′R′, trihalomethyl, halogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, arylalkyl, substituted arylalkyl, heteroarylalkyl and substituted heteroarylalkyl;
• each R′ is independently selected from the group consisting of —H, alkyl, heteroalkyl, alkenyl, alkynyl, aryl, arylalkyl, heteroaryl and heteroarylalkyl;
• or R4 and R5 taken together are —CH2—(CH2)n—CH2— where n is an integer from 0-6;
• or R2 and R3 taken together are —CH2—(CH2)n—CH2— where n is an integer from 0-6;
• with the proviso that when R1=methyl and R2═R3═R4═H then R5≠benzyl and;
• when R1═H, at least one of R2 and R3≠H.