Process for preparing 4-pyrimidinones

A process for preparing a compound represented by formula (I):

• ##STR8## in which R.sub.1 is selected from the group consisting of hydrogen, unbranched and branched C.sub.1-7 alkyl, unbranched and branched C.sub.3-9 alkenyl, and (C.sub.3-7)cycloalkyl(C.sub.1-6)alkyl groups, and R.sub.2 is selected from the group consisting of hydrogen, unbranched and branched C.sub.1-7 alkyl, (C.sub.3-7)cycloalkyl(C.sub.1-3)alkyl, aryl(C.sub.1-3)alkyl, aryloxy(C.sub.1-3)alkyl, arylthio(C.sub.1-3)alkyl, arylsulphonyl(C.sub.1-3)alkyl and heteroaryl (C.sub.1-3) alkyl groups, said process comprising the steps of reacting a compound of general formula (II):
• ##STR9## in which R.sub.1 is as defined above, with 1-bromo-4-(bromomethyl)benzene or 4-bromobenzaldehyde, and reducing the product compound formed to obtain a compound represented by formula (III):
• ##STR10## in which R.sub.1 is as defined above, reacting the compound represented by formula (III) with an amidine of general formula (IV):
• ##STR11## in which R.sub.2 is as defined above to obtain a compound represented by formula (V):
• ##STR12## in which R.sub.1 and R.sub.2 are as defined above, reacting the compound represented by formula (V) with a compound represented by formula (VI):
• ##STR13## to obtain a compound represented by formula (VII):
• ##STR14## in which R.sub.1 and R.sub.2 are as defined above, and deprotecting the compound represented by formula (VII) by removing the protecting group --C(CH.sub.3).sub.3 from the tetrazole moiety of the compound of formula (VII).