96089-31-5Relevant academic research and scientific papers
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
