25099-79-0Relevant articles and documents
CuCl-catalyzed radical cyclisation of N-α-perchloroacyl-ketene-N,S- acetals: A new way to prepare disubstituted maleic anhydrides
Cornia, Andrea,Felluga, Fulvia,Frenna, Vincenzo,Ghelfi, Franco,Parsons, Andrew F.,Pattarozzi, Mariella,Roncaglia, Fabrizio,Spinelli, Domenico
experimental part, p. 5863 - 5881 (2012/09/22)
The copper-catalyzed radical cyclization (RC) of N-α-perchloroacyl cyclic ketene-N,X(X=O, NR, S)-acetals was studied. While the RC of N-acyl ketene-N,O-acetals was unsuccessful, the 5-endo cyclization of the other ketene acetals provided much better results, with the following order of cyclization efficiency: hexa-atomic cyclic ketene-N,NR-acetalspenta-atomic cyclic ketene-N,S-acetalshexa-atomic cyclic ketene-N,S-acetals. Invariably the catalytic cycle begins with the formation of a carbamoyl methyl radical. This leads to a cascade of reactions, including a radical polar crossover step, which ends with the formation of the maleimide nucleus, or precursors of this. Products from the RC of the hexa-atomic cyclic ketene-N,S-acetals, were efficiently transformed into disubstituted maleic anhydrides.
SYNTHESIS OF 2-ALKYLPYRIMIDINES VIA 2-ALKYL-1,4,5,6-TETRAHYDROPYRIMIDINES
Pews, Richard Garth
, p. 1867 - 1872 (2007/10/02)
The condensation of 1,3-diaminopropane with alkanoic acids gives 2-alkyl-1,4,5,6-tetrahydropyrimidines.Dehydrogenation of the tetrahydropyrimidine derivatives over a palladium catalyst produces the 2-alkylpyrimidines in high yields.
