30190-45-5Relevant academic research and scientific papers
Novel salicylaldehyde-based mineral-supported expeditious synthesis of benzoxazin-2-ones
Yadav, Lal Dhar S.,Kapoor, Ritu
, p. 8118 - 8120 (2004)
One-pot montmorillonite K-10 clay supported reactions of either salicylaldehyde/2-hydroxyacetophenone hydrazones and aryl-/alkylureas or salicylaldehydes/2-hydroxyacetophenone and 4-aryl-/alkylsemicarbazides expeditiously yield 3,4-dihydro-4-hydrazino-2H-
Multistep solid-state organic synthesis of carbamate-linked covalent organic frameworks
Lyle, Steven J.,Osborn Popp, Thomas M.,Waller, Peter J.,Pei, Xiaokun,Reimer, Jeffrey A.,Yaghi, Omar M.
supporting information, p. 11253 - 11258 (2019/08/07)
Herein, we demonstrate the first example of a multistep solid-state organic synthesis, in which a new imine-linked two-dimensional covalent organic framework (COF-170, 1) was transformed through three consecutive postsynthetic modifications into porous, crystalline cyclic carbamate and thiocarbamate-linked frameworks. These linkages are previously unreported and inaccessible through de novo synthesis. While not altering the overall connectivity of the framework, these chemical transformations induce significant conformational and structural changes at each step, highlighting the key importance of noncovalent interactions and conformational flexibility to COF crystallinity and porosity. These transformations were assessed using 15N multiCP-MAS NMR spectroscopy, providing the first quantitation of yields in COF postsynthetic modification reactions, as well as of amine defect sites in imine-linked COFs. This multistep COF linkage postsynthetic modification represents a significant step toward bringing the precision of organic solution-phase synthesis to extended solid-state compounds.
A quick route for the synthesis of 3-Aryl-3,4-dihydro-2H-benz[e]-1,3- oxazin-2-ones
Shukla, Davender Kumar,Rani, Manju,Khan, Arif Ali
, p. 4537 - 4540 (2013/06/27)
N-(2-Hydroxy)-benzyl-arylamines (1) gave substantially pure 3-aryl-3,4-dihydro-2H-benz[e]-1,3-oxazin-2-one 2 on cyclization with carbonyldiimidazole in DMSO in 20-30 min at 20-25 °C in excellent yields.
Cyclization of substituted phenyl N-(2-hydroxybenzyl)carbamates in aprotic solvents. Synthesis of 4H-1,3-benzoxazin-2(3H)-ones
Mindl, Jaromir,Hrabik, Oldrich,Sterba, Vojeslav,Kavalek, Jaromir
, p. 1262 - 1272 (2007/10/03)
The kinetics of cyclization of substituted phenyl N-(2-hydroxybenzyl)carbamates and their N-methyl analogs, prepared by the reaction of 2-(aminomethyl)phenols with substituted phenyl chloroformates, was studied in dioxane or toluene at the temperatures 110-180 °C. Electron-withdrawing substituents in the leaving phenoxy group strongly accelerate the rate of cyclization (ρ = 2.45 ± 0.15) while the substituents in the other ring have virtually no effect. The cyclization was catalyzed with triethylamine in toluene but not in dioxane. On the basis of these results, the most convenient method for preparation of substituted 4H-1,3-benzoxazin-2(3H)-ones was a one-hour reflux of substituted 4-nitrophenyl N-(2-hydroxybenzyl)carbamates in dioxane. Based on the influence of substituents, solvents (dioxane and toluene) and triethylamine, the reaction mechanism and structure of the transition state were proposed.
