Compounds useful as promoters of SMN2

A method of treating or ameliorating one or more symptoms produced by Spinal Muscular Atrophy in a patient, comprising the step of administering to said patient a therapeutically effective amount of a compound of formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• X is O or S;
• R1 is a C1-6 aliphatic group, C6-10 aryl ring, heteroaryl ring having 5-10 ring atoms, or heterocyclyl ring having 3-10 ring atoms, each optionally substituted with 0-5 TR3;
• wherein each TR3 is independently halogen, CN, NO2, or an optionally substituted C1-4 alkyl, aryl, aralkyl, —N(R′)2, —CH2N(R′)—OR′, —Ch2OR′, —SR′, —CH2SR′,—COOR′,—NRCOR′,—CON(R′)2, or —S(O)2N(R′)2;
• each R2 is independently halogen, CN, NO2, or an optionally substituted C1-4 alkyl, aryl, aralkyl, —N(R′)3, —CH2N(R′)2, —OR′, CH2OR′, —SR′, CH2SR′, —COOR′, NRCOR′, —CON(R′)2, or —S(O)2N(R′)2;
• R′ is hydrogen or an optionally substituted C1-6 aliphatic group, an optionally substituted C6-10 aryl ring, an optionally substituted heteroaryl ring having 5-10 ring atoms, or an optionally substituted heterocyclyl ring having 3-10 ring atoms;
• and
• y is 0, 1, 2 or 3.