Selective inhibition of the monosynaptic spinal reflex by a series of hydroxylated alkylaminoindans

5-Hydroxy-2-piperidino-4,5,6,7-tetrahydroindan (5) and a number of related tetrahydro and dihydro compounds were prepared by selective mono- and dihydroxylation of the dihydro products from the Birch reduction of various alkylaminoalkylindans, tetralins, benzenes, and isoindolines. Some of these compounds showed a remarkably selective inhibition of monosynatpic spinal reflex in the segmental cat preparation.