94392-52-6Relevant academic research and scientific papers
Annulation of the Quinazoline Ring Utilizing Mesoionic Ring Systems
Potts, Kevin T.,Bordeaux, Kirk G.,Kuehnling, William R.,Salsbury, Ronald L.
, p. 1666 - 1676 (2007/10/02)
anhydro-3-Hydroxythiazoloquinazolin-4-ium hydroxides, prepared from the corresponding thioglycolic acid with cyclodehydrating agents and also from 4(3H)-quinazolinethiones and α-bromophenylacetyl chloride, were hydrolyzed at the 5-position of the quinazoline ring with hot water.Alkynic and alkenic dipolarophiles cycloadded readily in hot benzene; the former gave pyridoquinazolines and the latter 1:1 cycloadducts which lost H2S to give the above ring system.These procedures provided convenient annulation of a pyridinone to the c side of quinazoline.With ethyl acrylate, in addition to the normal 1:1 cycloadduct, a rearranged pyrroloquinazoline was obtained depending on the reaction conditions; analogous products were obtained with dimethyl fumarate. anhydro-1-Hydroxythiazoloquinazolinium hydroxides, preferably generated in situ from the corresponding thioglycolic acid and dicyclohexylcarbodiimide (DCC), and alkynic dipolarophiles in refluxing benzene readily gave pyridoquinazolines.Alkenic dipolarophiles also gave 1:1 cycloadducts, which lost H2S to form pyridoquinazolines, resulting in annulation of a pyridinone ring to the a side of quinazoline.
Carbenoid Intermediates in the Synthesis of Mesoionic Anhydro-4-hydroxythiazolium Hydroxides
Potts, Kevin T.,Murphy, Peter
, p. 1348 - 1349 (2007/10/02)
α-(Tosylhydrazono)phenylacetyl chloride and N-monosubstituted thioamides in dry, non-protic solvents and in the presence of Et3N give representatives of the title mesoionic ring system in good to excellent yields; carbene or carbenoid type intermediates a
