Indole-2,3-diones

C8H6N2O2 l/f-Indole-2,3-dione 3-oxime (8) Electrode sensor Photometric Li, Tl Transition metals 3, 80... 

The key intermediates 692 required for the thermal cyclization were prepared from the readily available indole-2,3-diones 693. The condensation of 693 with 3-methyl-4-phenylbut-3-en-2-one (694) afforded the 3-hydroxy derivatives 695. The dehydration of 695, followed by selective reduction of the 3,1 -double bond of compounds 696, provided the 3-alkyl derivative 697. Finally, the compounds 697 were transformed to the 3-(l,3-butadienyl)indoles 692 by reaction with an excess of ethyl chloroformate (Scheme 5.62). 

Keywords indole-2,3-dione, 2-pyrrolidone, microwave irradiation, spiro[indole-dipyrrolopyridines ]... 

A mixture of appropriate indole-2,3-dione 1 (2 mmol) and 2-pyrrolidone 2 (5 mmol) was introduced in a microwave oven and irradiated at 840 W till the completion of the reaction. Progress of the reaction was checked by TLC. Extraction with acetic acid and removal of the solvent afforded the product which was analyzed by 1H NMR and found to be of sufficient purity on TLC. 

Joshi et al. [81] have incorporated azetidin-2-one moiety into indole nucleus and synthesized several fluorine containing spiro-(3-lactams (Scheme 9). The synthesis involved the condensation of primary amines with an appropriate indole-2,3-dione... 

Isatin (lH-indole-2,3-dione) is a synthetically versatile substrate, where it can be used for the synthesis of a large variety of heterocyclic compounds, such as indoles and quinolines, and as a raw material for drug synthesis. Isatin has also been found in mammalian tissues, and its function as a modulator of biochemical processes has been the subject of several discussions. The advances in the use of isatin for organic synthesis during the last twenty-five years, as well as a survey of its biological and pharmacological properties are reported in this review and in the accompanying supplementary information. 

Isatin (lH-indole-2,3-dione, Figure 1) was first obtained by Erdman and Laurent in 1841 as a product from the oxidation of indigo by nitric and chromic acids. 

The Martinet procedure for the synthesis of indole-2,3-diones involves the reaction of an aminoaromatic compound and either an oxomalonate ester or its hydrate in the presence of an acid to yield a 3-(3-hydroxy-2-oxindole)carboxylic acid derivative which after oxidative decarboxylation yields the respective isatin. This method was applied with success for the synthesis of 5,6-dimethoxyisatin from 4-aminoveratrole whereas the use of 2,4-dimethoxyaniline was less successful40 (Scheme 9). 

Napthlylamine, when reacted with l,2,4-triazin-5-ones in acetic acid, gives benzo[e]indole-2,3-dione in 71 to 81% yields, but both aniline and 1-methylaniline fail to furnish the corresponding isatins. ... 

Isatin (indole-2,3-dione) [91-56-5] M 147.1, m 201-203 , 205 , pK >12 (acidic NH). Crystd from amyl alcohol and sublimed at 180°/lmm. In aq NaOH the ring opens to yield sodium o-... 

Isatin (lH-indole-2,3-dione) is an endogenous compoimd identified in humans. This class of compoimds possesses a wide range of biological activities [35] that include antiallergic, anticancer, anticonvulsant, antidiuretic, antithrombotic, antitubercular, antiviral, anxiogenic, immunosuppressant, muscle relaxant, and sedative activities. Vine et aL [36] synthesized a variety of isatin derivatives (XII) and evaluated their cytotoxic activities against the human monocyte-Uke histiocytic lymphoma (U937) ceU line in vitro. We used these cytotoxic data to develop QSAR Eq. 11 (Table 5) ... 

Isatin (177-indole-2,3-dione) has been used as a 1,2-dioxo compound in similar syntheses.135... 

Dioxo-2,6dihydroindole 2,3-Dioxoindoline EINECS 202-077-8 Indole-2,3-dione lndoline-2,3-dione 2,3-lndolinedione IH-Indole-... 

Thiophene, a colourless, water-insoluble liquid, with an odour like benzene, mp -38°C, bp 84°C, occurs in coal tar. It remains in the benzene fraction (benzene bp 80°C) on distillation of coal tar, and can be removed by extraction with cold concentrated sulphuric acid (see p 72). A solution of isatin (indole-2,3-dione) in concentrated sulphuric acid turns blue in the presence of thiophene (the... 

Indole-2,3-dione (isatin), red crystals, mp 204°C, is formed by the oxidation of indigo with nitric acid. It can be synthesized from o-nitrobenzoyl chloride via isatinic acid 45 ... 

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