87273-76-5

Upstream product

• 87273-75-4 3‐oxo‐N‐(4‐phenylthiazol‐2yl)butanamide 
• 2911-22-0 6-methyl-4-oxo-2-thioxo-3,4-dihydro-2H-1,3-oxazine 
• 70-11-1 α-bromoacetophenone 
• 87273-73-2 6-Methyl-2-(2-oxo-2-phenyl-ethylsulfanyl)-[1,3]oxazin-4-one 
• 87273-74-3 N-(4-phenylthiazol-2-yl)-3-aminocrotonamide 

Relevant academic research and scientific papers

S-PHENACYLATION OF 6-METHYL-4-OXO-2-THIO-2,3-DIHYDRO-4H-1,3-OXAZINE AND THE RING TRANSFORMATION OF THE S-PHENACYLATED COMPOUND

1,3-oxazine 1 reacted with phenacyl bromide in water using sodium hydroxide as a base to give S-phenacylated derivative 2, but the homogeneous conditions such as NaH in THF or NaOMe in methanol caused the base-induced cycloreversion of 1, resulting in the formation of thiocyanate 3.For the purpose of the intramolecular transformation to pyrimidine-fused heterocycle 11, 2 was treated with ammonia in refluxing ethanol, but gave amidamine 6 while 8 was obtained with ammonium acetate in refluxing acetic acid.Although the direct ring closure failed, the target 11 was finally synthesized by the cyclodehydration of ketamide 7 with phosphorus pentoxide at 250 deg C.