Compounds useful for treating neurological disorders

A method for treating a psychiatric disorder in a mammal comprising administering to the mammal, a therapeutically effective amount of a compound of formula [A]

• as racemic mixtures or as individual stereoisomers or mixtures of racemic and stereoisomers,
• wherein
• (i) X is selected from OH and NR1R2;
• (ii) R1, R2 are independently selected from H and C1-C6 alkyl;
• (iii) n is 0 or 1;
• and
• (iv) (a) R3, R4 are independently selected from H and C1-C6 alkyl;
• R5, R6 are independently selected from H and C1-C6 alkyl;
• or
• (b) one of R3 and R4, together with one of R5 and R6, form a cyclopropyl ring, and the other of R3, R4, R5 and R6 is selected from H and C1-C6 alkyl,
• including pharmaceutically acceptable salts, hydrates and solvates of the compound of formula [A], with the exclusion of the following compounds in racemic and stereoisomeric forms for treating migraine:
• propylisopropyl acetic acid, propylisopropyl acetamide, valnoctamide, valnoctic acid, diisopropyl acetamide
• wherein R1 and R2 are independently selected from H and C1-C6 alkyl.