Abstract: Ethylamine derivatives of the formula (I): (wherein R1 is hydrogen, hydroxyl, lower alkoxy or halogen; R2 is alkyl having 2 to 5 carbon atoms; R3 is hydrogen, alkyl having 2 to 5 carbon atoms, alkylcarbonyl having 2 to 5 carbon atoms, aryl having 6 to 10 carbon atoms or arylalkyl having 7 to 11 carbon atoms; the ring is a bicyclic compound which consists of at least one benzene ring and may comprise a saturated or unsaturated five- or six-membered ring which may or may not have heteroatoms, providing that when the ring is indole or 1,3-benzodioxole, R2 and R3 do not constitute, at the same time, two carbon atoms members, and when R3 is hydrogen, the ring is a bicyclic compound which is not indole, benzothiophene or benzodioxole and R2 is alkyl having 3 to 5 carbon atoms and pharmaceutically acceptable acid addition salts thereof. These compounds are promising as psychotropic drugs, antidepressants, drugs for Parkinson's disease and/or drugs for Alzeimer's disease.

Abstract: N-Cyano-N',S-ethylene-N'-([4-methyl-5-imidazolyl)methyl]isothiourea which is of value as an intermediate in the production of cimetidine and a process for its production are provided.

Abstract: There is provided a process for producing cyanoguanidine derivatives, especially N-cyano-N'-Methyl-N"-(4-methyl-5-imidazolylmethyl)thioethyl-guanidine.

Abstract: N-Cyano-N'-methyl-N"-(2-mercaptoethyl)-N"-[(4-methyl-5-imidazolyl)methyl]gu anidine and a method of producing the same are provided.

Abstract: A pharmacologically active cyanoguanidine derivative, generally referred to as cimetidine, is prepared by causing 4-methyl-5-hydroxymethylimidazole or a salt thereof to react with 2-substituted-1-methyl pyridinium salt and then causing the intermediate reaction product to react with N-cyano-N'-methyl-N"-(2-melcaptoethyl)-guanidine. The initial and subsequent reactions are carried out at room temperature under atmospheric pressure, using one and the same reaction vessel. No isolation of the intermediate reaction product resulting from the first reaction is required preparatory to the subsequent reaction. The recovery of the final intended product is carried out without using a column chromatography.