67073-93-2Relevant academic research and scientific papers
Elimination of 3-Hydroxy-2-nitro-2,3-dihydrobenzofurans to 2-Nitrobenzofurans
Ohishi, Yoshitaka,Doi, Yoshio,Nakanishi, Teruo
, p. 1336 - 1342 (2007/10/02)
β-Elimination of stereoisomeric cis- and trans-3-hydroxy-2-nitro-2,3-dihydrobenzofurans was investigated.The 2,3-dihydrobenzofurans were stable under acidic conditions but were easily dehydrated under basic conditions to afford the corresponding 2-nitrobenzofurans.An (E1cB)R mechanism is proposed on the basis of several lines of evidence obtained from studies on kinetics, ultraviolet spectra, leaving group effect and deuterium isotope effect in the elimination reaction.Keywords- 3-hydroxy-2-nitro-2,3-dihydrobenzofuran derivative; elimination; (E1cB)R mechanism; kinetic study; carbanion intermediate; leaving group effect; isotope effect;
A TYPICAL ElcB PROCESS IN THE ELIMINATION OF 3-HYDROXY-2-NITRO-2,3-DIHYDROBENZOFURANS TO 2-NITROBENZOFURANS
Ohishi, Yoshitaka,Doi, Yoshio,Nakanishi, Teruo
, p. 2598 - 2601 (2007/10/02)
It was clarified that the elimination of the 3-hydroxy-2-nitro-2,3-dihydrobenzofurans proceeded via a typical(ElcB)R mechanism in the presence of KOH to give the 2-nitrobenzofurans.
Reactions of Salicylaldehydes with Bromonitromethane
Ohishi, Yoshitaka,Doi, Yoshio,Nakanishi, Teruo
, p. 4260 - 4270 (2007/10/02)
Various salicylaldehydes were treated with bromonitromethane in the presence of an inorganic base to give 2-nitrobenzofuran derivatives, and the reaction mechanisms were investigated.The most remarkable feature of the reactions is that 3-hydroxysalicylaldehyde (1k) alone among various hydroxysalicylaldehydes (1b, k, n, r) gave 2-nitro-7-hydroxybenzofuran in good yield.Bromonitromethane reacted with salicylaldehydes at the aldehyde group exclusively to give 1-(2-hydroxyphenyl)-2-bromo-2-nitroethanols (14), followed by cyclization to produce mixtures consisting of cis- and trans-2-nitro-3-hydroxy-2,3-dihydrobenzofurans (8a, b; 9a, b; 10a, b).The stereochemistry of these products is discussed on the basis of the spectral data and chemical reactivities.The intermediates, 2,3-dihydrobenzofurans, underwent dehydration smoothly to give 2-nitrobenzofurans.Keywords - bromonitromethane; salicylaldehyde derivative; ring closure; 2-nitrobenzofuran derivative; cis-2-nitro-3-hydroxy-2,3-dihydrobenzofuran derivative; trans-2-nitro-3-hydroxy-2,3-dihydrobenzofuran derivative; 13C-NMR; stereochemistry; reaction mechanism
