The Condensation of (Chlorocarbonyl)Phenyl Ketene with Bisnucleophiles : Ketene Reactions

In this book, cycloaddition of chlorocarbonyl ketenes, effective 1,3-electrophiles in synthsis of heterocycles functionalized with oxo and hydroxyl groups, with 1,2 and 1,3-binucleophiles were described to prepare the five and six-membered heterocyclic compounds. Thus, (chlorocarbonyl)phenyl ketene (CCPK) was formed by distillation of phenyl malonyl chlorides by thermal dehydrohalogenation. Then to study the cycloaddition of this CCPK with enaminones as 1,3-binuleophiles, a series of substituted 5-acyl-2-pyridinone derivatives were prepared by this condensation and exhibited one tautomer. In countinuing, Schiff bases as 1,3-binucleophiles react with CCPK to produce the 2-(1H)-pyridinone derivatives and 1,3-oxazinium olate derivatives were also prepared by reaction of N-monosubstituted amide derivatives and CCPK when they are converted to other tautomeric forms. Finally, the pyrazole-trione derivatives were prepared by condensation of CCPK with N-unsubstituted pyrazolone derivatives as 1,2-binucleophile in mixture of two tautomers, but the 2-pyrone derivatives were produced by cycloaddition of CCPK with N-unsubstituted as 1,3-binucleophile in dry solvent and ambient temperature.