indole derivatives characterized by having a 1 , 3 , 4 , 9 - tetrahydropyranoindole or 1 , 3 , 4 , 9 - tetrahydrothiopyranoindole nucleus with a hydroxyalkanamine or lower alkoxyalkanamine substituent and a lower alkyl group at position 1 are disclosed . the nucleus is optionally further substituted at position 9 and on the aromatic ring . the derivatives are useful diuretic agents , and methods for their preparation and use are also disclosed .