FIELD: organic chemistry and technology, pharmacy. SUBSTANCE: invention relates to [(benzodioxane, benzofuran and benzopyrane)-alkyl- -substituted guanidines of the formula (I) 
, their pharmaceutically acceptable salts, or their stereochemical isomers where X is O, CH2 or direct bond; R1 is H, C1-C4-alkyl; R2 is H, C1-C6-alkyl, C3-C6-alkenyl, C3-C6-alkynyl; R3 is H, C1-C4-alkyl; or R2 and R1 taken together can form bivalent radical of the formula -(CH2)m where m = 4 or 5; or R1 and R2 taken together can form bivalent radical of the formula -CH=CH- or -(CH2)n where n = 2, 3 or 4; or R3 can means a bond when R1 and R2 taken together form bivalent radical of the formula -CH=CH-CH=, -CH=CH-N= or -CH-N=CH= where one or two hydrogen atoms are substituted with halogen atom, C1-C6-alkoxy-group, C1-C6-alkyl, CN, NH, mono- or di-(C1-C6-alkyl)-amino-group, aminocarbonyl, C1-C6-alkylaminocarbonylamino-group; R4 is H or C1-C6-alkyl; Alk1 means bivalent C1-C3-alkanediyl radical; A means bivalent radical of the formula (A) 
, (b) 
, (c) 
, (d) 
, (e) 
where each R5 is H or C1-C4-alkyl where each R6 is H or C1-C4-alkyl; Alk2 means C2-C15-alkanediyl or C5-C7-cyclo- -alkanediyl and each p = 0, 1, 2; R7 and R8 each means independently H, halogen atom, C1-C6-alkyl, hydroxyl, C1-C6-alkyl-hydroxycarbonyl, C1-C6-alkoxy-group, cyano-group, amino-C1-C6-alkyl, carboxyl, nitro- or amino-group, aminocarbonyl, C1-C6-alkylcarbonyl-amino-group or mono- or di-C1-C6-alkylamino-group at condition that [2-[(2,3-dihydro-1,4-benzodioxine-2-yl)-methyl]-amino] - -ethylguanidine is excluded. Invention describes pharmaceutical preparations containing the derivatives of guanidine as active components, methods of synthesis of the guanidine derivatives and a new p-cyanoguanidine, and intermediate compounds that can be used as vasoconstrictors. EFFECT: improved method of synthesis, enhanced effectiveness of compounds. 14 cl, 10 tbl, 30 ex
