Dioxindoles

We recently demonstrated that organolithium reagents formed by directed metallation of pivaloylanilines would react rapidly with carbon monoxide at 0°C or room temperature to form high yields of dioxindoles (Fig. 16) (ref. 30). This... 

Filter, recrystallize the precipitate from boiling water and dry to get the dioxindole (III). To a stirred slurry of 1.9 g lithium aluminum hydride in 100 ml dry ether add 4.3 g (111) in 120 ml dry benzene and reflux four hours. Cool and carefully add a little water. When bubbling stops, filter and dry, evaporate in vacuum the organic layer to get (IV). 

Trichloroethane, Trichloroethylene Dioxanol, see 1,4-Dioxane Dioxanone, see 1,4-Dioxane Dioxindole, see Indole 2,2 -Diphenic acid, see Phenanthrene Diphenyl disulfide, see Fonofos... 

Sodium hydrosnlfite has been used to reduce 5-bromo and 5,7-dibromoisatin244 as well as 5-methoxy-l-methylisatin57 to the corresponding dioxindole (65). Reduction of 1-benzylisatin with sodium hydrosulfite led to the dioxindole (65, R = H, R = CH2Ph)111,245 and the isatide (66).245 1,7-Trimethyleneisatin110 underwent a similar... 

Isatin and its derivatives have reacted with both aryl and alkyl Grignard reagents to give 3-alkyl (or aryl) dioxindoles (178).232,497-500 Use of an excess of phenylmagnesium bromide with A-benzyl501 and... 

R = H oxindole-3-acetic acid R OH dioxindole-3-acetic acid... 

The products of partial reduction of isatin, dioxindole and oxindole, have been widely... 

Anthranilate, as well as isatin, isatoic anhydride, dioxindole and oxindole have been... 

In the reaction of isatins with some cyclic ketones, such as 4-hydroxy-2H-benzopyran-2-one, the initial dioxindole formed reacts with a second equivalent of the ketone yielding a 3,3-disubstituted oxindole. 

The dehydration of the dioxindoles can be achieved by treatment with a mixture of HC1 and AcOH424,425. The 3-methyleneoxindoles can be selectively reduced at the carbon-carbon double bond using Na2S2C>4 in aqueous ethanol (Scheme 97). 

Isatin has been used in the determination of the enzymatic activity of ketopantoyl-lactone reductase587"590 and other fungal carbonyl reductases591"594, as it is a substrate of these enzymes that is reduced to a dioxindole in a reaction that can be monitored by colourimetry. Ketopantoyl-lactone reductase, also named as isatin hydrolase, can be used to remove unwanted isatin from the broth of the microbial production of indigo595 596. 

The formation of oxindol and dioxindol by reduction of isatin is, however, more in favour of the following constitution for these compounds —... 

Martinet dioxindole synthesis. Formation of derivatives of dioxindole from esters of mesoxal-ic acid and aromatic amines or amino quinolines. 

G. A. Russell, C. L. Myers, P. Bruni, F. A. Neugebauer, and R. Blankespoor, Semidiones. X. Semidione radical anions derived from indan-2.3-dione, coumaran-2.3-dione, thianaphthalenequi-none, isatin, and IV-hydroxy isatin. Nitroxide radicals derived from isatin, dioxindole, oxindole, and other indole derivatives, /. Am. Chem. Soc. 92, 2762-2768 (1970). 

Oxindol—C.H,NO—is obtained from dioxindol by reduction with Na amalgam in acid solution. It crystallizes in easily soluble, colorless needles, and oombinco with acid and basoa... 

R H 0XIND0LE-3-ACETIC ACID R = H 6-HYOROXY-OXINDOLE-3-ACET1C ACID R = OH DI0XIND0LE-3-ACETIC ACID R = OH 5-HYDROXY-DIOXINDOLE-3-ACETIC ACID... 

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