134209-94-2

Upstream product

• 21367-45-3 propan-2-one 4-(4-methoxy-phenyl)-semicarbazone 
• 79-36-7 dichloroacethyl chloride 
• 21449-53-6 5,5-Dimethyl-2-(4-methoxy-phenylimino)-Δ³-1,3,4-oxadiazolin 
• 134209-87-3 (5,5-dimethyl-5H-[1,3,4]oxadiazol-2-ylidene)-(4-methoxy-phenyl)-amine 

Downstream Products

• 67-64-1 acetone 

Relevant academic research and scientific papers

Spiro-fused β-lactam oxadiazolines by formal cycloaddition of 2-imino-Δ3-1,3,4-oxadiazolines to ketenes

Sixteen spiro-fused β-lactam oxadiazolines were prepared by treatment of 2-imino-Δ3-1,3,4-oxadiazolines with carboxylic acid chlorides in the presence of triethylamine.Two others were prepared by methylation of β-lactam oxadiazoline anion equivalents with methyl iodide.Isomer ratios, spectra, stereochemistry, and relative thermodynamic stabilities of a pair of diastereomeric β-lactam oxadiazolines are reported.Three cases of failure of the approach are noted, to define some of the limitations.The oxadiazolines are known to undergo thermolysis, in solution, to afford N2, a ketone, and a β-lactam-4-ylidene.Phenyl substitution at C5 of the oxadiazoline ring serves to decrease the thermolysis temperature by about 50 deg C but it also leads to the onset of a side reaction that lowers the yield of ylidene.This observation indicates a limitation of the oxadiazoline approach to the generation of β-lactam-4-ylidene.

β-Lactam-4-ylidenes

β-Lactam-4-ylidenes, generated by thermolysis of easily accessible spiro-fused β-lactam oxadiazolines, are trapped in typical intramolecular and intermolecular carbene reactions.