Alkynes and Poly(ethylene glycol) Derivatives as Nucleophiles and Catalysts in Substitution Reactions of 1-Chloroanthraquinones

Article abstract of DOI:10.1021/jo00025a021

Two synthetically useful approaches to 1-substituted anthraquinone derivatives are reported.Application of these methods afforded the following 1-anthraquinyl ethers: n-propyl, n-butyl, n-octyl, n-nonyl, n-hexadecyl, isoamyl, allyl, 2-butenyl, (E)-2-hexenyl, (E)-2-tridecyl, benzyl, phenyl, 4-methylphenyl, 2-butynyl, 2-pentynyl, 2-hexynyl, 3-pentynyl, 3-hexynyl, 3-heptynyl, 3-nonynyl, 4-hexynyl, 4-heptynyl, 5-heptynyl, 5-octynyl, 5-nonynyl, 2-methoxyethyl, 2-(2-methoxyethoxy)ethyl, 2-<2-<2-(octadecyloxy)ethoxy>ethoxy>ethyl, 2-(methylthio)ethyl, 2-(1-piperidino)ethyl, and 2-(1-morpholino)ethyl.The results of about 100 nucleophilic substitution reactions (a number were duplicates) are presented.Most of these reactions involve either a new approach, new products, or both.Includes are displacements of chloride by alkanols, alkenols, and alkynols.Of the three, only the latter afford acceptable yields of product, although lower yields are observed as the distance between hydroxyl and triple bond increases.Nucleophiles of the type RO(CH2CH2O)nOH proved remarkably effective.Alkynyl ethers and poly(oxyethylene) ethers also proved to be excellent leaving groups.Both alkynols and oligoethylene glycol monoethers were found to be catalysts for the conversion of 1-chloroanthraquinone into 1-anthraquinyl ethers.In an attempt to understand the mechanism of this reaction, solid-state structures of four anthraquinone derivatives have been obtained.These have poly(ethyleneoxy), morpholino, or alkynyl side arms.