The present invention is concerned with vasoconstricive [(benzodioxan, benzofuran or benzopyran)alkylamino]alkyl substituted guanidines having the formula

the pharmaceutically acceptable acid addition salts thereof, and the stereochemically isomeric forms thereof, wherein Xis O, C¾ or a direct bond; R¹ is hydrogen or Ci-6alkyl; R² is hydrogen, Ci -6alkyl, C3-6alkenyl or C3-6alkynyl; R³ is hydrogen or Ci-6alkyl; or R² and R³ may be taken together to form a bivalent radical of formula -(CH2)_m-, wherein m is 4 or 5; or R¹ and R² taken together may form a bivalent radical of formula -CH=CH- or of formula -(0¾)_η-, wherein n is 2, 3 or 4; or R³ may represent a bond when R¹ and R² taken together form a bivalent radical of formula -CH=CH-CH=, -CH=CH-N=, or -CH=N-CH=; R⁴ is hydrogen or Ci-oalkyljAlk¹ is a bivalent Ci-3alkanediyl radical; A is a bivalent radical of formula :

(a) (b) (c)

(d) (e)
wherein each R⁵ is hydrogen or Ci^alkyl; wherein each R⁶ is hydrogen or Ci_4alkyl; Alk² is C2-i5alkanediyl or C5.7cycloalkanediyl; and each p is 0, 1 or 2; provided that [2-[(2,3-dihydro- l,4-benzodioxin-2-yl)methyl]amino]ethyl guanidine is excluded. Pharmaceuticals which are useful as vasoconstrictors. Compositions comprising said guanidine derivatives as active ingredients, processes for preparing said guanidine derivatives and novel N-cyano guanidine, intermediates; and a use as a medicine are described.