"1-HYDROXYALKANAMINE PYRANO (3,4-BETA) INDOLE DERIVATIVES"

The invention concerns new compounds of formula I in which R is lower alkyl; R is hydrogen or lower alkyl; R and R each independently is hydrogen, lower alkyl, halo, nitro, trifluoromethyl or lower alkoxy; R and R each independently is hydrogen or lower alkyl or R and R together with the nitrogen atom form a pyrrol-1-yl, piperidino or morpholino ring; R is hydrogen or lower alkyl; Alk and Alk each independently is a straight or branched chain lower alkylene having one to six carbon atoms; and X is oxa or thia, and therapeutically acceptable acid addition salts thereof. The above compounds are diuretic agents, which also possess anti-hypertensive activity. They may be used alone or with other diuretic agents. Pharmaceutical compositions containing the compounds and processes for preparing the compounds are also described.