M.M. Sidky

Reaction of di- and trialkyl phosphites with isatins

Abstract Isatins (Ia–c) react with dialkyl phosphites to produce the corresponding dioxindole-3-phosphonic esters (IIa–i). 4:5-Benzocoumaran-2, 3-dione (III), the oxygen analogue of 4:5-benzoisatin reacts similarly with diethyl phosphite giving the α-hydroxyphosphonate (IV). Trialkyl phosphites effect the conversion of the isatins (Ia–c) into colourless 2:1-adducts, believed to have structure similar to VII or the corresponding cyclic saturated oxyphosphorane (VIII). The IR and NMR spectra of the adducts are in favour of the proposed structures.

Reactions with organophosphorus compounds—III : Reactions of Di-, and trialkyl phosphites with 1,2,3-indantrione, and 2-benzylidene-1,3-indandione

Abstract 1,2,3-Indantrione (II) reacts with dialkyl phosphites, yielding colourless 2:1 adducts, believed to have structure III. 2-Benzylidene-1,3-indandione (IX) reacts with diethyl phosphite, forming 1:1 adduct, having structure X. The action of triethyl phosphite on IX in benzene solution has been investigated and the resulting 1:1 adduct could have structure XIII. The UV, IR and NMR spectra of the adducts are in favour of the proposed structures.

Organophosphorus compounds—XVI: The reaction of phosphite esters with vicinal triketone monohydrates

Abstract Trialkyl phosphites react with the monohydrates of 1,2,3-indantrione (ninhydrin) (VII) and 1,3-diphenylpropanetrione (VIII) to give the corresponding phosphate derivatives XIa–c and XVIIIa–c. The same compounds are obtained upon reacting VII and/or VIII with the proper dialkyl hydrogen phosphite. The trialkyl phosphites cause the quantitative reduction of perinaphthindantrione (IX) and/or its monohydrate (X) producing dihydroxy-peri-naphthindenone (XXI). On the other hand, dialkyl hydrogen phosphites add to IX (or X), yielding compounds XXIIa–c. Structural reasonings based on UV, IR and NMR spectral data are presented.

Reactions with substituted xanthones—VI : Infrared spectra of hydroxy-9-xanthones, hydroxy-10-thiaxanthones and some related compounds

Abstract Synthesis of 6′-substituted-4′-pyrono (2′,3′-1,2)-(IIa and IIb), 4′,5′-dihydro-4′-4-oxofurano (2′,3′-1,2)-(IIIb and IIIc), 4′,5′-dihydro-5′-methylfurano (2′,3′-2,1)-(VI) and 4′,5′-dihydro-5′-methylfurano (2′,3′-4,3)-9-xanthones (VII) is described. The infrared absorption spectra of a number of hydroxy-9-xanthones, hydroxy-10-thiaxanthones and new extended xanthone systems are briefly discussed.

Organophosphorus compounds—VIII : The reaction of alkyl phosphites and diphenylphosphino-dithioic acid with 2-benzylidene-3(2H)-thianaphthenone-1,1-dioxides

Abstract The reaction of 2-benzylidene-3(2 H )-thianaphthenone-1,1-dioxides (VI) with trialkyl phosphites depends upon the reaction medium. In phenol, compounds having structure VII are produced. In benzene, the 1:1 adducts isolated, wre believed to have a structure similar to X or the corresponding cyclic oxy-phosphorane (XI) which is readily converted into VII by the action of phenol. Dialkyl phosphites react with VI to give the 1:1 adducts (VII) and diphenylphosphinodithioic acid adds to the 2-benzylidenes (VI) in molar ratios to give compounds assigned structure XIV. The IR and NMR spectra of the adducts are recorded.

Reactions with organophosphorus compounds—IV : Reaction of di-, and trialkyl phosphites with 1,2-benzophenazine-3,4-quinone

Phenanthraquinone (II) reacts with dimethyl phosphite to give the corresponding o-quinolmonophosphate (IV). The action of dialkyl phosphites on 1,2-benzophenazine-3,4-quinone (V) in benzene solution has been investigated, and the colourless 1:1-adducts, formed on the cold, believed to have structure similar to IX or X. In boiling benzene, a mixture of yellow 1:1-adducts (VIf-h) and red-violet 1:1-adducts (VIIc-e) is obtained. Trimethyl phosphite as well as o,o-dimethyl hydrogen phosphorodithioate (CH3O)2P(S)SH effects the reduction of the quinone (V) to 3,4-dihydroxy-1,2,-benzophenazine (VIa). The IR spectra of the adducts are recorded.

Spaltungsreaktionen mit organischen Disulfiden

Triphenylarsin reagiert mit aktiven organischen Disulfiden in siedendem Xylol oder im Sonnenlicht unter Bildung der entsprechenden Monosulfide und von Triphenylarsinsulfid. Die Entmethylierung von Khellin und Visnagin durch Einwirkung von organischen Disulfiden im Sonnenlicht wird diskutiert.