SYNTHESIS AND [4-(N-ALLYL-N-ARYL)AMINO-1,3-DIAZA-1,3-BUTADIENES WITH VINYLKETENES, ISOPROPENYLKETENES AND CHLOROKETENES - ENTRY TO NOVEL PYRIMIDINONE FUSED PYRIMIDINONE DERIVATIVES(2]CYCLOADDITION REACTIONS OF4)

4-(N-Allyl-N-aryl)amino-1,3-diaza-1,3-butadienes 2, prepared by the tr eatment of N-arylamino-1,3-diaza-1,3-butadienes 1 with allyl bromide, underwent [4+2] cycloadditions with vinyl/isopropenyl- and accompanied by rearrangements in case of chloroketenes, to yield 5-vinyl/isoprope nyl pyrimidinones 5 and 5-methylthio pyrimidinones 19, respectively. T he pyrimidinones 5 on refluxing in xylene gave pyrimidoazepines 6, und erwent annelation reaction, in refluxing benzene in presence of AlCl3, to yield pyrimidoquinolines 7 and on treatment with DMAD in refluxing toluene, underwent [4+2] cycloaddition accompanied by the elimination of N-allylarylamine functionality to yield quinazolinone 9. Further. the reactions of 5 with PhSH in the presence of AIBN in refluxing benz ene followed unusual radical cyclisation involving N-aryl group leadin g to pyrimidoquinolines 10. The iodocyclisation of pyrimidinones 19 yi elded pyrimidothiazines 20. (C) 1997 Elsevier Science Ltd.