5780-08-5Relevant articles and documents
A convenient synthesis of tri- and tetramethylbenzaldehydes from readily available phenols
Dhankher, Persis,Sheppard, Tom D.
supporting information, p. 381 - 384 (2014/03/21)
This letter describes a convenient synthesis of the six isomeric tri- and tetramethylbenzaldehydes, which are not readily available from major chemical suppliers. Formylation of readily available phenols via electrophilic aromatic substitution provides compounds containing the correct aromatic substitution pattern. ?Suzuki cross-coupling of the corresponding trifluoromethanesulfonates with methylboronic acid then provides the benzaldehydes as single isomers. Georg Thieme Verlag Stuttgart. New York.
NATURE OF THE REDUCING AGENT AND MECHANISM OF THE REDUCTIVE CONDENSATION OF TRICHLOROMETHYLARENES WITH HYDROXYLAMINE AND HYDRAZINES IN PYRIDINE
Belen'kii, L. I.,Poddubnyi, I. S.,Krayushin, M. M.
, p. 726 - 736 (2007/10/03)
It was shown that during the reductive condensation of trichloromethylarenes with hydroxylamine or hydrazines in pyridine the event of reduction with replacement of one chlorine atom by a hydrogen atom occurs without the participation of hydroxylamine or hydrazine.The first step of the reaction is the formation of N-(α,α-dichloroarylmethyl)pyridinium chlorides, which are converted by the action of the chloride anion or a second pyridine molecule to the corresponding 4-substituted 1,4-dihydropyridines.The latter undergo further aromatization with transfer of hydrogen from the 4-position of the dihydropyridine ring to the benzyl dichloromethylene group and the formation of N-(α-chloroarylmethyl)-4-chloropyridinium chlorides or N-(α-chloroarylmethyl)-4-(pyridino)pyridinium dichlorides, which give the corresponding aldehydes in hydrolysis or products of reductive condensation under the action of hydroxylamine or hydrazines.
An Unexpected γ-Hydrogen Rearrangement in the Mass Spectra of Di-ortho-substituted Alkylbenzenes
Kingston, Eric E.,Eichholzer, John V.,Lyndon, Paul,MacLeod, John K.,Summons, Roger E.
, p. 42 - 47 (2007/10/02)
In contradiction of long-accepted mass spectrometric dogma, the site-specific γ-hydrogen rearrangement is observed in alkylbenzenes in which both ortho positions are blocked with methyl substituents.Mass spectrometric studies of a series of five trimethyl- and three tetramethylisopentylbenzenes have shown that this rearrangement is only suppressed to a significant degree in those compounds in which all three positions ortho and para to the isopenyl group are blocked.Deuterium labelling has confirmed the γ-site-specific origin of the migrating H atom while metastable studies have been used to investigate the mechanism of the rearrangement process.
