Schiff bases of mono- and dinitro-2-acylthiophenes with n-amino-heterocyclic compounds

摘要

The invention comprises compounds of the formula FORM:0748440/IV(a)/1 wherein R is hydrogen or a nitro-group, R1 is hydrogen or a lower alkyl radical having 1 to 8 carbon atoms inclusive, NR2 represents a saturated five or six-membered heterocyclic ring containing one or two nuclear nitrogen atoms and which may contain one nuclear oxygen atom. Such compounds are obtained by heating a mono- or di-nitro-2-acylthiophene with an N-amino derivative of a heterocyclic compound with a five or six-membered ring containing one or two nuclear nitrogen atoms and which may also contain a nuclear oxygen atom, in a solvent, or with the hydrochloride of the N-amino-derivative in the presence of an alkali metal acetate in an aqueous solution. Radicals which -NR2 may represent are 1-hydantoyl of the formula FORM:0748440/IV(a)/2 wherein R3 and R4 are alike or different and may be hydrogen or lower alkyl and X represents oxygen or sulphur, or -NR2 may represent 1-piperidyl, 4-morpholyl or 1-pyrrolidyl. In Examples: (1) 5-nitro-2-thiophenecarboxaldehyde is refluxed in aqueous alcohol containing sodium acetate with 1-amino-hydantoin hydrochloride to give 1-[N-(5-nitro-2-thenylidene)-amino]-hydantoin; (2) 5-nitro-2-thiophenecarboxaldehyde and 1 - amino - 2 - thiohydantoin are refluxed in alcohol to give 1-[N - (5 - nitro - 2 - thenylidene) - amino] - 2-thiohydantoin. Similarly prepared are (3) 1-[N - 3,5 - dinitro - 2 - thenylidene) - amino] - 5-methyl-hydantoin; (4) N-[5-nitro-2-(a -ethyl)-thenylidene]-1-amino-piperidine and (5) N-[3,5-dinitro - 2 - (a - methyl) - thenylidene] - 4-amino-morpholine.