A compound of Formula (I): wherein: R1 is C1-6 alkyl, benzyl, or (CH2)n—C(O)NH2; wherein the benzyl may be unsubstituted or substituted by one or two C1-6 alkyl, halogen, C1-6 alkoxy, or methylenedioxy groups; R2 is benzimidazolyl, quinolinyl, benzofuranyl, napthyl, indolyl, benzothiophenyl, phenyl, furanyl, thienyl, or pyridyl substituted or unsubstituted by one, two or three halogen, C1-3 alkyl, C1-3 alkoxy, or methylenedioxy groups; X1 and X2 are independently hydrogen, halogen, C1-3 alkyl, C1-3 alkoxy, nitro, CF3, or CN; n is 1, 2, or 3; m is 1, 2 or 3; or a pharmaceutically acceptable salt thereof.