Ethyl-5-hydroxy-2-methylindole

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). ... 

C12H12N2 1,1 diphenylhydrazine 530-50-7 582.21 51.836 2 23856 C12H13N03 ethyl 5-hydroxy-2-methylindole-3-carboxylate 7598-91-6 568.15 50.469 2... 

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). 

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. 

Ifenprodil (= l-Methyl-2-hydroxy-2-(4-hydroxyphenyl) ethyl-1 -(4-benzyl-piperidine)] -(aryl piperidine) [at(/o-3-(Indol-2-yl)-8-methyl-8-azabicyclo-[3.2.1] octane] (indolotropane) [Kynurenic acid (= 4-Hydroxy-2-quinolinecarboxylic acid)] (quinoline carboxylic acid) [Memantine (= 1-Amino-3,5 dimethyladamantane)] (amino adamantane, amino cyclic aliphatic) [Methadone (= 6-Dimethylamino-4,4-diphenyl-3-heptanone)] (aryl tertiary amine) [em/o-3-(l -Methylindol-2-yl)-8-methyl-8-azabicyclo-[3.2.1] octane(indolotropane) exo- 3-( 1 -Methylindol-2-yl)-8-methyl-8-... 

Even though the proposed mechanism does not preclude formation of 4-alkyl-5-hydroxyindoles, no examples were known until Allen and Weiss isolated ethyl 4-carbomethoxy-5-hydroxy-2-methylindole-3-carboxy-late (22) from the reaction of 2-carbomethoxy-l,4-benzo-quinone (20) with ethyl 3-aminocrotonate, following... 

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