Verfahren zur Herstellung neuer, halogensubstituierter Tetrahydrochinazoline

1,131,164. 1,2,3,4 - Tetrahydroquinazoline derivatives. DR. KARL THOMAE G.m.b.H. 13 April, 1967 [20 April, 1966], No. 17098/67. Heading C2C. Novel 1,2,3,4 - tetrahydroquinazoline derivatives of the general formula wherein Hal represents a chlorine or bromine atom; R1 represents a hydrogen, chlorine or bromine atom; R2 represents a straight or branched chain C 1 -C 5 alkyl group, a hydroxyalkyl, alkoxyalkyl, dialkylamino, cycloalkyl, hydroxycycloalkyl, pyridalkyl or aralkyl group; and R3 represents a hydrogen atom, an alkyl or an aryl group; and physiologically compatible acid addition salts thereof are prepared (a) when R3 represents a hydrogen atom, by reaction of a 2-amino-benzylamine derivative of the formula with formaldehyde, (b) by reduction of a quinazoline derivative of the formula wherein X represents two hydrogen atoms or an oxygen atom with a metal hydride; (c) when R3 represents a hydrogen atom or an alkyl group and R1 is a chlorine or bromine atom, by chlorination or bromination of a 1,2,3,4-tetrahydroquinazoline of the formula wherein R3 represents a hydrogen atom or an alkyl group; or (d) when R5 is a hydrogen atom, by reduction of a 1,2,3,4, - tetrahydroquinazolone-(2) of the formula with a metal hydride; followed by optional conversion to a physiologically compatible acid addition salt of the product. Pharmaceutical compositions having antipyretic, anti-tussive and secretolytic activity comprise as active ingredient at least one 1,2,3,4 - tetrahydroquinazoline derivative of the first general formula above or a physiologically compatible acid addition salt thereof in association with a pharmaceutical carrier or excipient. 1,2,3,4 - Tetrahydroquinazolones - (2) of the fifth formula above are prepred by reaction of 2-amino-benzyl-amines of the second formula above with phosgene.