Patent GB-698976-A (GB)
Title: Derivatives of 3,4,5,6-tetrahydropyrimidine
IPC: C07D239/06
Filed: 1951-05-31
Abstract: The invention comprises compounds of formula <FORM:0698976/IV (b)/1> in which at least one of the R's is an alkyl radicle and each of the remaining R's and each of the R1's are either a hydrogen atom or a hydrocarbon radicle, and their salts.  Preferably they are made by reacting an alkyl substituted benzoic acid with an alpha-gamma-alkylene-diamine (or salt thereof) in the presence of a dehydration catalyst.  Instead of the acid the corresponding halide, anhydride, amide or ester may be used.  Catalysts specified are p-toluene sulphonic and sulphuric acids.  They are normally present in an amount of about 0.001-0.1 mole./mole. of acid reactant. Preferably the diamine is present in excess. Temperatures specified are 50-400 DEG  C. with continuous removal of water.  The following are representative of many compounds stated to be preparable: 2-p-tolyl-, 2-(2,4-dimethylphenyl)-, 2-(3-methyl-4-biphenylyl)-, 2-p - tolyl - 4,4,6 - trimethyl -, 2 - p - octylphenyl - 6 - phenyl - and 2 - tolyl - 4 - (2 - phenyl) - propyl - 6 - methyl - 3,4,5,6 - tetrahydropyrimidine. Preferably all substituents other than the alkyl phenyl substituent are hydrogen atoms or alkyl groups. Benzoic, toluic, acetic; hydrochloric, sulphuric and phosphoric acids are specified for salt formation.  In examples in which p-toluenesulphonic acid is used as catalyst p-tert-butyl-benzoic acid is reacted with (1) 2-methyl-2,4-diamino-pentane; and (2) trimethylenediamine to give 2-p-tert-butyl-phenyl - 4,4,6 - trimethyl - and 2 - p - tert - butylphenyl - 3,4,5,6 - tetrahydropyrimidine respectively; (3) methyl-p-toluate with the diamine of (1) gives the p-toluic acid salt of the product of (1) from which the free base may be recovered and in (4) p-octylbenzoic acid and (5) 3,5-ditertiary butylbenzoic acid are reacted with the diamine of (1) to yield precipitates from which the corresponding pyrimidines may be liberated.ALSO:2-Alkaryl-3,4,5,6,? tetrahydropyrimidines of formula <FORM:0698976/V/1> in which at least one of the R's is an alkyl radicle and each of the remaining R's and each of the R1's are either H or a hydrocarbon radicle are used as stabilizers for rubber and in asphalt compositions.  Preferably all substituents other than the alkyl phenyl substituent are hydrogen atoms or alkyl groups. Representative of many specified components are 2-p-tolyl-, 2-(2,4-dimethylphenyl)-, 2-(3-methyl 4-biphenylyl)- 2- p-tolyl-4, 4, 6- trimethyl-, 2- p-octylphenyl- 6- phenyl and 2- tolyl- 4- (2- phenyl)- propyl? 6- methyl- 3, 4, 5, 6- tetrahydropyrimidine.ALSO:2 - Alkaryl - 3,4,5,6 - tetrahydropyrimidines of formula <F\1> in which at least one of the R's is an alkyl radicle and each of the remaining R's and each of the R1's are either hydrogen or a hydrocarbon radicle are soluble in organic liquids e.g. hydrocarbon oils, to yield fungicidal compositions. Representative of many specified compounds are 2-p-tolyl-, 2-(2,4-dimethylphenyl)-, 2-(3-methyl-4-biphenylyl-, 2-p-tolyl-4,4,6-trimethyl-, 2-p-octylphenyl-6-phenyl- and 2-tolyl-4-(2-phenyl)-propyl-6-methyl-3,4,5,6-tetrahydropyrimidine. Preferably all substituents other than the alkyl phenyl substituent are hydrogen atoms or alkyl groups.  Specified salts are those with benzoic, toluic, acetic, hydrochloric or phosphoric acids.