5-Hydroxy-3-methylindole

Miki and Hachiken reported a total synthesis of murrayaquinone A (107) using 4-benzyl-l-ferf-butyldimethylsiloxy-4fT-furo[3,4-f>]indole (854) as an indolo-2,3-quinodimethane equivalent for the Diels-Alder reaction with methyl acrylate (624). 4-Benzyl-3,4-dihydro-lfT-furo[3,4-f>]indol-l-one (853), the precursor for the 4H-furo[3,4-f>]indole (854), was prepared in five steps and 30% overall yield starting from dimethyl indole-2,3-dicarboxylate (851). Alkaline hydrolysis of 851 followed by N-benzylation of the dicarboxylic acid with benzyl bromide and sodium hydride in DMF, and treatment of the corresponding l-benzylindole-2,3-dicarboxylic acid with trifluoroacetic anhydride (TFAA) gave the anhydride 852. Reduction of 852 with sodium borohydride, followed by lactonization of the intermediate 2-hydroxy-methylindole-3-carboxylic acid with l-methyl-2-chloropyridinium iodide, led to the lactone 853. The lactone 853 was transformed to 4-benzyl-l-ferf-butyldimethylsiloxy-4H-furo[3,4- 7]indole 854 by a base-induced silylation. Without isolation, the... 

A solution of 1.05 M diborane in THF (25 ml, 26 mraol) was added slowly to a stirred suspension of 3-acetyl-5-hydroxy-2-methylindole (1.0 g, 5.3 mmol) in THF (10 ml). After hydrogen evolution ceased, the mixture was heated at reflux for I h, cooled and poured into acetone (75 ml). The mixture was heated briefly to boiling and then evaporated in vacuo. The residue was heated with methanol (50ml) for 20min. The solution was concentrated and 3NHC1 (40ml) was added. The mixture was extracted with ether and the extracts dried (MgSO ) and evaporated to yield a yellow oil. Vacuum sublimation or recrystallization yielded pure product (0.76 g, 82%). 

In 1929, Nenitzescu reported that p-benzoquinone (4) was treated with ethyl 3-aminocrotonate (5) in boiling acetone to yield ethyl 5-hydroxy-2-methylindole-3-carboxylate (6). ... 

Similarly, iV,A/ -dimethyl-3,3 -bisindolylmethane (169) has been used in a related experiment, where treatment thereof with trifluoroacetic fflihydride (TFAA) in diethyl ether at room temperature yielded a mixture of products from which the trifluoromethyl-substituted indolo[3,2-b]carbazole 170 was isolated as the major pentacyclic component, accompanied by the hydroxy derivative 171 as well as small amounts of the indolo[2,3-h]carbazole 146 (Scheme 20). The precursor 169 could also be prepared in situ from A-methylindol-3-methanol under... 

Chemical Name 4-(2-Hydroxy-3-isopropylaminopropoxyl)-2-methylindole Common Neme —... 

The 4-hydroxy-2-methylindole (MP 112°C to 115°C from benzene/ethyl acetate), used as starting material, may be obtained by hydrogenation of 4-banzyloxy-2-dimethylamino-methylindole (MP 117°C to 120°C from benzene) in the presence of a palladium catalyst (5% on aluminum oxide). 

Ci HjqNjOj 63235-39-2) see Procaterol 4-[2-hydroxy-3-[(l-methylethyl)amino]propoxy]phenol (C,2H 9N03 62340-37-8) see Prenalterol 2-hydroxy-2-methyl-3-(4-fluorophenylthio)propionicacid (CiqHuFOjS) see Bicalutamidc 4-hydroxy-2-methylindole... 

This is the most convenient method of preparing indole-3-acetic acid if an agitated autoclave is available. The method can be used to prepare other indole-3-acetic acids from a-hydroxy acids. For example, a-methylindole-3-acetic acid has been prepared by condensing indole with lactic acid. 

D. J. Smith, M. L. Appleton, J. R. Carlson, G. S. Yost, Identification of /3-Glucuronidase-Resistant Diastereomeric Glucuronides of 3-Hydroxy-3-methyloxindole Formed During 3-Methylindole Metabolism in Goats , Drug Metab. Dispos. 1996, 24, 119 - 125. 

To 10 mL of a stirred solution of LAH (1 M in THF under N2), there was added dropwise a solution of 0.57 4-acetoxyindol-3-yl-N-ethyl-N-methylglyoxylamide in 10 mL anhydrous THF. When the addition was complete, the reaction mixture was brought to a reflux for 15 min. After cooling to 40 °C, sufficient water was added to decompose both the reaction complex and the excess hydride. After filtration through Celite (under an N2 atmosphere), the solvent was removed under vacuum, and the solid residue recrystallized from /hexane to provide 0.18 g (41%) N-ethyl-4-hydroxy-N-methylindole (4-HO-MET) with a mp 118-119 °C. Anal C,H,N. 

In common with other peroxide oxidations, indole is oxidized by potassium persulfate at pH 5 to 6 to give 3-hydroxyindole O-sulfate, which is hydrolyzed with some difficulty to yield indolin-3-one, whilst the analogous oxidation of 3-methylindole produces 3-methyloxindole, together with a mixture of the isomeric 4-, 5-, 6- and 7-hydroxy-3-methylindoles (79HC(25-3)l). 

Condensation of formyl-pyrroles and -indoles with a wide range of other activated methylene compounds has been reported. These include, for example, hydantoin, which provides a useful synthetic route to tryptophane and j8- (pyrrolyl)alanines, thiohydantoin, rhodanine and AT-substituted barbituric acids (B-77MI30505, 79HC(25-3)357). Flash pyrolysis of the condensation product derived from 3-formyl-2,5-dimethylpyrrole with Meldrum s acid produces 6-hydroxy-2-methylindole, (440) — (441) (74AJC2605), whilst the analogous... 

The infrared spectra of over 20 1-oxygenated indoles have been collected [79MI1 see also 78JCS(P1)1117]. In the 1-hydroxy compounds, the positions of the HO bands are sensitive to both the conditions of measurement and to the other substituents present, and hydrogen bonding may or may not be observed. For example, l-hydroxy-2-methylindole in nujol shows a sharp peak at 3415 cm-1 and a broad band between 2230 and 3385 cm-1, while in carbon tetrachloride, the corresponding bands for nonbon-ded and bonded hydroxyl appear 3510 and 2300-3450 cm-1. The range for unbonded and bonded hydroxyl appears to be between 3100 and 3510 cm"1 and (broad absorption) between 2230 and 3450 cm"1, respectively. 

The H-NMR Spectra of I-Hydroxy-2-Methylindole (78) and 2-Methyl-3W-Indole I-Oxide (80) in 8 (J in Hertz) from Internal Me4Si [70JCS(C)I067]... 

Attempted oxidation of 3-cyano-l-hydroxy-2-methylindole (111) by cold aqueous potassium permanganate or sodium dichromate in hot acetic acid caused deoxygenation to 3-cyano-2-methylindole, and photolysis of the 0-acetyl and 0-methoxycarbonyl derivatives gave the same product... 

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