Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
A versatile method of synthesis of the quaternary benzo [c] phenanthridine alkaloid (1), having a tertiary benzo [c] phenanthridine skeleton, from the norbase (3) is described. Treatment of the norbase (3) with sodium borohydride in formic or in acetic acid gave the N-methyl-(5) or the N-ethyl-(7) dihydrobase, respectively, in good yield. The N-methyldihydrobase (5) could also be prepared by treatment of the norbase (3) with sodium borohydride and dimethyl sulfate in hexamethylphosphoric triamide. The dihydrobases (5 and 7) were readily convertible to the corresponding quaternary benzo [c] phenanthridine alkaloids by oxidation with Jones reagent or with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) in good yields. In addition, we found that the air-oxidation of the carbanions derived from the ψ-cyanides (11) of the quaternary bases (1) gave the corresponding oxybases (10) in excellent yields.
Abstract Reaction of the ethylene glycol monoesters (I) with 1,1,2,3,3,3‐hexafluoropropyldiethylamine (PPDA) (II) yields mixtures of the corresponding monofluorides (III) and the tetrafluoropropionates (IV).
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
For the sake of establishment of a versatile synthetic method for benzo [c] phenanthridine alkaloids, improvement of the Robinson synthetic method was examined. Thirteen chalcones (7a-m) were prepared by condensation of two acetophenone derivatives (15 and 16) with eleven benzaldehyde derivatives (19a-k) as fundamental starting materials. Hydrocyanation of these chalcones (7a-l) except one (7m) gave the corresponding 2, 4-bisaryl-4-oxobutyronitriles (8a-l). Eleven 2, 4-bisaryl-4-oxobutyramides (9a-k) were also prepared.
