83257-96-9Relevant academic research and scientific papers
SYNTHESIS, 1H AND 13C NMR SPECTRA, AND DYNAMIC STEREOCHEMISTRY OF 2-MONOSUBSTITUTED AND 2,2-DISUBSTITUTED 4-ARYL(ALKYL)CARBAMOYL-3,4,5,6-TETRAHYDRO-1,3,4-OXADIAZINES
Samitov, Yu. Yu.,Gadzhiev, G. Yu.,Dzhalilov, E. Yu.,Nematollahi, J.
, p. 1329 - 1336 (2007/10/02)
Six-membered heterocyclic compounds are formed in the reaction of aromatic isocyanates with 2-hydroxyethylhydrazones.For example, 2,2-dimethyl-4-(p-tolylcarbamoyl)-3,4,5,6-tetrahydro-1,3,4-oxadiazine is formed in the reaction of (CH3)2C=NNHCH2CH2OH with p-CH3C6H4N=C=O.Twelve new compounds were obtained similarly from substituted β-hydroxyethylhydrazones and p- and o-tolyl isocyanates and isothiocyanates.The structure of the products was proved by IR, 1H and 13C NMR, and mass spectra.In the case of 2,2-dimethyl-4-(p-tolylcarbamoyl)-3,4,5,6-tetrahydro-1,3,4-oxadiazine the barrier to inversion of the ring, ΔG 65 kJ/mole, was determined by the dynamic NMR method.At temperature of -5 deg C and below this compound exists preferentially in the chair conformation with an equatorial 4-(p-tolylcarbamoyl) group.
