This invention provides compounds of the formula: ##STR00001## wherein R.sub.1 and R.sub.2 are each, independently, H, alkyl, cycloalkyl, --CH.sub.2-cycloalkyl, alkoxy, halogen, fluorinated alkyl, --CN, --NH--SO.sub.2-alkyl, --SO.sub.2--NH-alkyl, alkyl amide, amino, alkylamino, dialkylamino, fluorinated alkoxy, acyl, or phenoyl or thiophenoyl; R.sub.3 and R.sub.4 are each, independently, H, alkyl or cycloalkyl; R.sub.5 is H or alkyl; R.sub.6 is H or; and the dashed line indicates an optional double bond; or a pharmaceutically acceptable salt thereof, and pharmaceutical compositions and methods utilizing these compounds for the treatment or prevention of disorders including obsessive-compulsive disorder, depression, anxiety, generalized anxiety disorder, schizophrenia, migraine, sleep disorders, eating disorders, obesity, epilepsy, and spinal cord injury.