DERIVATI AMMIDINICI

New pharmacologically active amidino derivatives as muscarinic receptor blocking agents which are useful for the treatment of gastrointestinal disorders of the following formula A- @ = N-R1 (I) wherein R represents hydrogen atom, C1-5 alkyl, aryl, an amino group optionally substituted by one or two C1-5 alkyl; R1 represents hydrogen atom, C1-8 alkyl, aralkyl; A represents C1-5 alkyl substituted by 2 or 3 radicals, which may be identical or different from each other, selected from aryl, cycloalkyl, carboxamide; or a saturated 6-membered heterocyclic ring containing one nitrogen atom N-substituted by COR2 where R2 is a methyl substituted by 2 or 3 radicals, which may be identical or different from each other, selected from aryl, cycloalkyl, hydroxy; or where R3 is hydrogen atom and R4 is C1-5 alkyl substitued by 2 or 3 radicals, which may be identical or different from each other, selected from aryl, cycloalkyl, carboxamide, or by hydroxy optionally esterified with a cycloalkylcarboxylic acid, or R3 and R4, together with the nitrogen atom to which they are attached, form a saturated 5- to 7-membered heterocyclic ring, optionally containing one or two nitrogen atoms or an endocyclic carboxamido group optionally comprising in its inside -CH2-CH2- or being the heterocyclic ring substituted by a C1-5 alkyl substituted in turn by 2 or 3 radicals, which may be identical or different from each other, selected from C1-5 alkyl, aryl, cycloalkyl or hydroxy, or byarylalkylene, or by -OR5 where R5 is -OCR6 where R6 is methyl substituted by 2 or 3 radicals, which may be identical or different from each other, selected from a saturated or unsaturated C1-5 alkyl, aryl, cycloalkyl, hydroxy C1-5 alkyl, hydroxy, or unsaturated 6-membered heterocyclic ring, provided that at least one between R and A is amino group or The tautomers and the acid addition salts of these compounds, as well as the process for the preparation of the compounds of formula (I) and pharmaceutical compositions containing them are also described.