59346-36-0

Upstream product

• 1003-73-2 3-picoline-N-oxide 
• 103-71-9 phenyl isocyanate 

Downstream Products

• 43191-22-6 3-methyl-N-phenyl-2-aminopyridine 
• 59346-38-2 7a-methyl-3-phenyl-3a,4,5,7a-tetrahydro-3H-oxazolo[4,5-b]pyridin-2-one 

Relevant academic research and scientific papers

Reaction of Aromatic N-Oxides with Dipolarophiles. X. Role of Charge-Transfer Complexes in 1,3-Dipolar Cycloaddition of Pyridine N-Oxides to Phenyl Isocyanate

In the 1,3-dipolar cycloaddition reaction of 3-methylpyridine N-oxide with phenyl isocyanate, spectroscopic evidence indicates that phenyl isocyanate forms charge transfer complexes with both pyridine N-oxide and aromatic solvents such as pyridine.In connection with the charge-transfer complex formation, the solvent effect on the site selectivity was investigated.The most prominent solvent effect was observed in the reaction using 3-methylpyridine as a solvent.The equilibrium constants for the interaction of 3-methylpyridine N-oxide with phenyl isocyanate in several solvents were found to be quite large, indicating that the reaction mixtures favor complex formation.The proton nuclear magnetic resonance (1H-NMR) spectra of the mixtures show a high field shift of the methyl signal of 3-methylpyridine N-oxide due to charge-transfer complexation.Based on these results, the structure and role of the complexes are discussed.Keywords - charge-transfer complex; 1,3-dipolar cycloaddition; pyridine N-oxide; phenyl isocyanate; site selectivity; visible absorption spectra; equilibrium constant; frontier molecular orbital; kinetics

Reaction of Aromatic N-Oxides with Dipolarophiles. VI. Further Studies on the 1,3-Dipolar Cycloaddition Reaction of Pyridine N-Oxides with Phenyl Isocyanates

To provide additional evidence for the concerted mechanism postulated for the 1,3-dipolar cycloaddition reaction of pyridine N-oxides with phenyl isocyanates, kinetic studies on the cycloaddition reactions were conducted in a variety of solvents.The cycloaddition showed low sensitivity to the ionizing power of the medium, indicating that it proceeds by a mechanism which involves very little change in charge separation between the ground state and the transition state.The observed cycloadditivity and site selectivity are discussed in terms of the following controlling factors based on MINDO/3 calculations: HOMO-LUMO control, secondary orbital interaction, steric interaction, dipole-dipole interaction and charge-transfer complexation. Keywords - 1,3-dipolar cycloaddition; pyridine N-oxide; phenyl isocyanate; kinetics; frontier molecular orbital; solvent effect