5319-71-1

Upstream product

• 2431-91-6 4-methoxy-2,6-dimethylphenol 
• 1310558-96-3 3-quinazolin-4-one-N-oxyl radical 
• 950-99-2 2,2,5,7,8-pentamethylchroman-6-ol 
• 128-37-0 2,6-di-tert-butyl-4-methyl-phenol 
• 489-01-0 2,6-Di-t-butyl-4-methoxyphenol 
• 2374-05-2 4-bromo-2,6-dimethyl-phenol 
• 576-26-1 2.6-dimethylphenol 
• 527-60-6 Mesitol 
• 22900-79-4 N-(3,5-dimethyl-4-hydroxyphenyl)-acetamide 
• 106910-72-9 1,2-dihydro-3-hydroxy-2-(2-hydroxy-1-naphthyl)quinazolin-4(3H)-one 

Downstream Products

• 4797-76-6 3-benzyloxyquinazolin-4(3H)-one 

Relevant academic research and scientific papers

Importance of π-stacking interactions in the hydrogen atom transfer reactions from activated phenols to short-lived N-oxyl radicals

A kinetic study of the hydrogen atom transfer from activated phenols (2,6-dimethyl- and 2,6-di-tert-butyl-4-substituted phenols, 2,2,5,7,8- pentamethylchroman-6-ol, caffeic acid, and (+)-cathechin) to a series of N-oxyl radical (4-substituted phthalimide-N-oxyl radicals (4-X-PINO), 6-substituted benzotriazole-N-oxyl radicals (6-Y-BTNO), 3-quinazolin-4-one-N-oxyl radical (QONO), and 3-benzotriazin-4-one-N-oxyl radical (BONO)), was carried out by laser flash photolysis in CH3CN. A significant effect of the N-oxyl radical structure on the hydrogen transfer rate constants (kH) was observed with kH values that monotonically increase with increasing NO-H bond dissociation energy (BDENO-H) of the N-hydroxylamines. The analysis of the kinetic data coupled to the results of theoretical calculations indicates that these reactions proceed by a hydrogen atom transfer (HAT) mechanism where the N-oxyl radical and the phenolic aromatic rings adopt a π-stacked arrangement. Theoretical calculations also showed pronounced structural effects of the N-oxyl radicals on the charge transfer occurring in the π-stacked conformation. Comparison of the kH values measured in this study with those previously reported for hydrogen atom transfer to the cumylperoxyl radical indicates that 6-CH3-BTNO is the best N-oxyl radical to be used as a model for evaluating the radical scavenging ability of phenolic antioxidants.

Cyclisation of Schiff Bases containing Amide or Hydroxamic Acid Groups to 1,2-Dihydroquinazolin-4-ones; Thermal Decomposition Reaction of the 1,2-Dihydroquinazolin-4-ones

2-Hydroxynaphthalene-1-carbaldehyde reacts with o-aminobenzamide in methanol to produce the Schiff base (1a) whereas reaction with 2-aminobenzohydroxamic acid leads directly to the dihydrohydroxyquinazolinone (2b).The Schiff base (1b), an intermediate in the formation of (2b), can be isolated (in an impure form) by quenching the reaction with water.When refluxed in dichlorobenzene the dihydrohydroxyquinazolinone (2b) decomposes in part by carbon-carbon bond fission to give 3-hydroxyquinazoline-4(3H)-one (5) and 2-naphthol and to a lesser extent by dehydration leading to the quinazolinone (4).The dihydroquinazolinone (2a) is readily prepared by cyclisation of the Schiff base (1a) and decomposes thermally to give quinazolin-4(3H)-one (9) and 2-naphthol.A mechanism for the carbon-carbon bond cleavage observed in the thermal decompositions is proposed.