Ketene 2 -pyrimidinones

The [4-I-2] cycloaddition of ketenes 628 with 1,3-diazabutadienes 629 is now a well-established route to 5,6-dihydro-4-pyrimidinones 630 and, when a leaving group is present, 4-pyrimidinones 631 <1997X13841, 1998H(47)933, 2001 H(55>2283, 2002ARK(vii)106, 2002J(P1)774>. 

Mono-and disubstituted ketenes react with N-imidoyl phosphoranimines (19) to give pyrimidinone (20) and quinazoline (21) derivatives ... 

Aryl-6-phenyl-2-methylthio/secondary amino substituted-4(3//)-pyrimidinones were derived from a reaction of N-arylamino substituted 1,3-diaza-1,3-butadienes with substituted ketenes that was analyzed by computational methods <97T13829>. 1,3-Diazines related to 6-amino-4-chloro-5-cyano-2-(dimethylamino)pyrimidine were prepared in one-pot fashion from 1,1-diamino-2,2-dicyanoethylene and phosgeniminium chloride <97SC1223>. Pyrazolo[3,4- /]pyrimidines were derived from 4-substituted 5-aminopyrazole-l-carbothioamides <97JCR(S)352>. Amino-5-(trifluoromethyl)-l,2,4-triazole gave polysubstituted 2-... 

N-Condensed 5,6-dihydro-4(3H)-pyrimidinone ring from ketenes... 

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