93449-57-1Relevant academic research and scientific papers
Substituent and solvent effects on the proton transfer equilibrium in anils and azo derivatives of naphthol. Multinuclear NMR study and theoretical calculations
Alarcón, Sergio H.,Olivieri, Alejandro C.,Sanz, Dionisia,Claramunt, Rosa M.,Elguero, José
, p. 1 - 9 (2007/10/03)
The tautomeric equilibrium due to proton transfer is compared in a series of anils of 2-hydroxynaphthalene-1-carbaldehyde and azo derivatives of 2-naphthol. Although structurally similar, these systems suffer different substituent effects on the solution-state proton transfer properties. The comparative study was performed using 1H, 13C and 15N NMR spectroscopy in a variety of solvents. Hartree-Fock ab initio calculations involving relative stability of tautomers and full geometry optimization for the ground state are in agreement with the experimental observations.
Waste-free chemistry of diazonium salts and benign separation of coupling products in solid salt reactions
Kaupp, Gerd,Herrmann, Andreas,Schmeyers, Jens
, p. 1395 - 1406 (2007/10/03)
Gas-solid and solid-solid techniques allow for waste-free and quantitative syntheses in the chemistry of diazonium salts. Five techniques for diazotations with the reactive gases NO2, NO and NOCl are studied. Two types are mechanistically investigated with atomic force microscopy (AFM) and are interpreted on the basis of known crystal packings. The same principles apply to the cascade reactions that had been derived from one-step reactions. Solid diazonium salts couple quantitatively with solid diphenylamine and anilines to give the triazenes. Azo couplings are achieved with quantitative yields by cautious co-grinding of solid diazonium salts with β-naphthol and C-H acidic heterocycles, such as barbituric acids or pyrazolinones. Solid diazonium salts may be more easily applied in a stoichiometric ratio for couplings in solution. Co-grinding of solid diazonium salts with KI gives quantitative yields of various solid aryl iodides. The unavoidable coupling products in salt reactions are completely separated from the insoluble products in a highly benign manner. The solid-state reactions compare favourably with similar solution reactions that produce much waste. The structures of the products are elucidated with IR and NMR spectroscopy and mass spectrometry, while the tautomeric properties of the compounds are studied with density functional calculations at the B3LYP/6-31G* and BLYP/6-31G** levels.
