Open Collections

The synthesis of some secondary amyl and hexyl homologues of dinitro ortho and para cresols

University of British Columbia

Eight new dinitro secondary amyl and hexylphenols of unequivocal structure were synthesized and characterized by their piperidine, morpholine and cyclohexylamine salts. The first step in the syntheses was the esterification of phenol to give phenyl acetate and phenyl propionate. A high temperature Fries rearrangement in the absence of solvent was used to convert the phenyl esters to o- and p-hydroxyaceto- and propiophenones. The alkyl o- and p-hydroxyphenyl ketones were then methylated with dimethylsulphate in an alkaline medium. The resulting methoxyacetophenones and methoxypropiophenones were reacted with Grignard reagents prepared from n- and isopropyl bromides. The tertiary alcohols thus obtained were dehydrated by refluxing in toluene, in the presence of iodine. The water in the water-toluene azeotrope was collected in a Dean and Stark tube. Nitrosyl chloride derivatives of the alkenes were prepared whenever possible, and analyzed for nitrogen. The alkenes were dissolved in ethanol and hydrogenated under 1000 p.s.i. pressure at 50° C. The resulting alkylanisoles were characterized as sulphonamides which were analyzed for both nitrogen and methoxyl content. The para alkylanisoles were demethylated by refluxing with pyridine hydrobromide at 200° C. The ortho alkyl anisoles were demethylated by refluxing with constant boiling hydriodic acid and phenol. The resulting alkylphenols were characterized as 3,5-dinitrobenzoate derivatives which were analyzed for nitrogen. The alkylphenols were nitrated to the dinitro derivativeswith concentrated nitric acid (density 1.50) in glacial acetic acid at -15° C. The piperidine, morpholine and cyclohexylamine salts were prepared by the addition of the amine to a benzene solution of the nitrophenol. The amine salts were analyzed for nitrogen. The alcohols, alkenes and alkylanisoles were analyzed for methoxyl values. Carbon and hydrogen analyses for the alkylphenols were also obtained. The phenols prepared were: 2-(o- and p-hydroxyphenyl)-pentane, 2-(o- and p-hydroxyphenyl)-3-methylbutane, 3-(o-and p-hydroxyphenyl)-hexane, 3-(o- and p-hydroxyphenyl)-2-methylpentane. A sample of "o-sec-amylphenol” obtained from Sharpies Chemicals Inc. was found to consist mainly of 2-(o-hydroxy-phenyl)-pentane. A Fries rearrangement of phenyl trimethyl acetate (phenyl pivalate) gave phenol as the only identifiable product, together with possible degraded and polysubstituted mixtures. o-Hydroxytrimethylacetophenone (o-hydroxypivalophenone) could not be separated or identified in the distillate.

Text

2012-02-28

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/40973

Chemistry

University of British Columbia

Graduate