Patent GB-894384-A (GB)
Title: 4,7-diamino-n-aralkyl-2-aryl-6-pteridinecarboxamides
IPC: C07D475/10
Filed: 1960-04-05
Abstract: The invention comprises substituted pteridines of the general formula <FORM:0894384/IV (b)/1> wherein R1 represents a phenyl radical or a phenyl radical mono-substituted by a lower alkyl, lower alkoxy chloro, bromo, or nitro substituent, or a furyl, thienyl or pyridyl radical, Alk represents an alkylene radical containing from 1 to 6 carbons, R2 and R3 each represent hydrogen or a lower alkyl radical, R4 represents a phenyl or thienyl radical or a radical of the formula <FORM:0894384/IV (b)/2> and R5 and R6 each represent a nitro, hydroxy, amino, lower alkyl or lower alkoxy radical or chlorine or bromine (the lower alkyl and lower alkoxy radicals are aliphatic radicals having a maximum of 4 carbon atoms), and the preparation thereof by reacting the required 4,6-diamino-2-aryl-5-nitrosopyrimidine with an N-aralkyl-a -cyanoacetamide of the general formula <FORM:0894384/IV (b)/3> wherein Alk and R1 have the above significance, in an organic solvent in which the reactants are soluble, such as a lower alcohol, b -ethox - ethanol or dimethylformamide-preferably in the presence of an alkali metal alkoxide.  Detailed examples are given.  4,6 - Diamino - 2 - aryl - 5 - nitrosopyrimidines of the general formula <FORM:0894384/IV (b)/4> wherein R2 and R3 and R4 have the above significance, are prepared by treating andR4 substituted amidine hydrochloride (a) with a slight excess of silver salt of isonitrosomalononitrile and cyclizing the resulting amidine salt to form a 4-unsubstituted amino-6-amino-2-aryl-5-nitrosopyrimidine, or (b) with a lower alkyl cyanoacetate to form a 6-amino-2-aryl-4-pyrimidol, reacting this compound with a chlorinating agent such as phosphorus pentachloride, thionyl chloride or phosphorus oxychloride to form a 6-amino-2-aryl-4-chloro-pyrimidine, treating this compound with the required alkylamine to form a 4-alkylamino-6-amino-2-aryl-pyrimidine, and treating this compound with sodium nitrite and acid at a low temperature to form a 4 4-alkylamino-6-amino-2-aryl-5-nitrosopyrimidine.  N-aralkyl-a -cyanoacetamides of the general formula <FORM:0894384/IV (b)/5> wherein R1 represents a phenyl, a phenyl monosubstituted by lower alkyl, lower alkoxy, chloro, bromo or nitro, a furyl, a thienyl or a pyridyl radical, are prepared by reacting a lower alkyl ester of a -cyanoacetic acid with at least a molar equivalent of the required aralkylamine.  The lower alkyl and lower alkoxy radicals are aliphatic radicals having a maximum of 4 carbon atoms).  R4 substituted amides, wherein R4 represents a radical of the formula <FORM:0894384/IV (b)/6> in which R5 and R6 represent lower alkyl, lower alkoxy, nitro, hydroxy, amino, bromo and chloro substituents (the lower alkyl and alkoxy radicals have the above significance, are prepared (a) in the case of substituents in the meta- or para-positions by passing dry hydrogen chloride into an alcohol solution of the required benzonitriles, treating the solid material thus obtained with dry ammonia, and then with hydrohalic acid to form the hydrohalide of the amidine, and (b) in the case of substituents in the orthopositions by treating the required o-substituted benzonitriles with an excess of hydroxylamine hydrochloride in the presence of an alkali metal alkoxide, hydrogenating the resulting o-substituted benzamidoxime, and isolating the desired amidine in the form of a hydrohalide salt.