114365-83-2

Upstream product

• 123-75-1 pyrrolidine 
• 10562-42-2 3,3-dichloro-1-phenyl-propenone 
• 540-72-7 sodium thiocyanide 
• 2290-65-5 trimethylsilyl isothiocyanate 
• 81836-52-4 (2-Chlor-2-pyrrolidino-vinyl)phenylketon 
• 513-74-6 ammonium dithiocarbamate 

Downstream Products

• 114365-82-1 6-Phenyl-4-pyrrolidino-1,3-oxazin-2-on 

Relevant academic research and scientific papers

Synthesis of 4-Amino-1,3-oxazine-2-ones and 4-Amino-1,3-oxazine-2-thiones via Electrocyclic Ring Closure

The title compounds 3 and 4 are easily obtainable by reaction of 2-acyl-1-chloro-enamines 2 with trimethylsilyl-isocyanate, trimethylsilyl-isothiocyanate or sodium rhodanide, respectively.Primarily formed acylvinyl-iso(thio)cyanates D, G spontaneously undergo electrocyclization.A one-pot operation leads directly to 4-amino-1,3-oxazine-2-thiones 4 starting from acylketenedichlorides 1 via 2 by successive addition of secondary amine and sodium rhodanide.Reaction of 2 with ammonium dithiocarbamate results in an unexpected formation of 4.Treatment of 4 with mercuric acetate offers a further access to 4-amino-1,3-oxazine-2-ones 3.Finally, 3 are obtained from 2 on the sequence of ammonolysis to acylketeneaminals 5 and phosgenation.Characteristic scopes and limitations as well as mechanistic features of these transformations are discussed. - Keywords: 1,3-Oxazine-2-ones; 1,3-Oxazine-2-thiones; Acylketenedichlorides; Acylketeneaminals; 2-Acyl-1-chloro-enamines; Electrocyclic reactions; Acylmigration