876345-31-2Relevant academic research and scientific papers
Facile and selective synthesis of chloronicotinaldehydes by the Vilsmeier reaction
Gangadasu,Narender,Bharath Kumar,Ravinder,Ananda Rao,Ramesh,China Raju,Jayathirtha Rao
, p. 8398 - 8403 (2007/10/03)
Eleven enamides were prepared by adopting different procedures. The various enamides prepared were subjected to Vilsmeier reaction using (i) POCl3/DMF; (ii) diphosgene/DMF; (iii) triphosgene/DMF leading to the formation of various multisubstituted chloronicotinaldehydes. Studies carried out indicate that Vilsmeier reagent concentration and the replacement of POCl3 by diphosgene or triphosgene, provides excellent selectivity and higher yields. Under modified reaction conditions one can get only chloronicotinaldehydes and not the chloropyridines as products. The various advantages in using diphosgene and triphosgene are illustrated. The mechanism of formation of chloronicotinaldehyde was discussed.
