Tetrahydro-y-carboline

Tetrahydro-y-carbolines may be prepared by an internal Mannich-type reaction between 2-j8-aminoethyhndoles and formaldehyde. Kebrle et al. prepared 27 by the reaction of 2-lithio-l-methyl-indole with A-benzyl-A-ethylaminoacetone followed by debenzyl-ation treatment of 27 with formaldehyde led to the formation of the tetrahydro-y-carboline 28. Similarly, when the quaternary salts (30) of the Mannich bases (29) are heated at 100°, 1,2,3,4-tetrahydro-y-carbohnium salts (31) are formed. 

Variously substituted 1,2,3,4-tetrahydro-y-carbolines (43c) may be obtained readily from 4-piperidone phenylhydrazones (43b). In fact, probably the first appbcation of the Fischer... 

Tetrahydrocarboline derivatives have recently been synthesized from 2-o-nitroarylated cyclohexanone derivatives. Thus, reductive cyclization of 3-(2,4-dinitrophenyl)-l-methyl-4-piperidone (68) (prepared by the reaction of 2,4-dinitrochlorobenzene with l-methyl-4-A-pyrrolidmo-3-piperideine) gave 7-amino-2-methyl-l,2,3,4-tetrahydro-y-carboline (69). Neither catalytic nor chemical reduction of the... 

The reduction of 2-methyl-1,2,3,4-tetrahydro-y-carboline (92) with zinc and hydrochloric acid in the presence of mercuric chloride gives the indolenine derivative, 2-methyl-l,2,3,4,4a,9b-hexahydro-y-carbo-line (93). A related compound, 4,9b-diethyl-2-methyl-l,2,3,4,4a,9b-hexahydro-y-carboline (96), was obtained by catalytic hydrogenation of 95, which was prepared by Fischer ring closure of the phenyl-hydrazone 94. The stereochemistry of the B/C ring junction in these... 

In an elegant investigation, the stable free radicals 2,4-dinitrophenyl hydrazone of 2,2,6,6-tetramethyl-4-piperidoue nitrogen oxide (1) and 2,2,4,4-tetramethyl-l,2,3,4-tetrahydro-y-carboline-3-oxyl (2) were used... 

This was followed by two other alternative syntheses of racemic horsfiline, one based on an oxidative rearrangement of the tetrahydro-y-carboline derivative 62 (Scheme 4) and another involving a spirocyclization between the 2-oxo-5-melhoxytryptamine derivative 63 and formaldehyde (Scheme S) [61]. 

Pyrido[3,2-c] indoles, tetrahydro-, (tetrahydro-y-carbolines), general review 73KGS291. 

Pyrido[2,3-h]indoles (a-carbolines), synthesis and reactivity of 84KGS435. Pyrido[2,3-c]indoles (/S-carbolines), biochemistry of 83MIIO. Pyrido[3,2-c]indoles, tetrahydro- (tetrahydro-y-carbolines) 73KGS291. 3//-Pyrrolo[2,3-c]quinolines 78H(9) 1617. 

The structural state of membranes was studied by EPR-spectroscopy using paramagnetic spin probes [8], Rat and mice blood erythrocytes and mice EAC cells were incubated in the presence of ichfan for 45 min then, probes were inserted. The microviscosity of various membrane sites was measured on an ER 200D-SRC spectrometer (Bruker, Germany). Probe I (2.2.6.6-tetramethyl-4-capryloyl-oxypiperidine-l-oxyl) is localized mainly in the surface lipid bilayer of membrane probe II (5.6-benzo-2.2.6.6-tetramethyl-1.2.3.4-tetrahydro-y-carboline-3-oxyl) permeates into deep-located near-protein sites of the lipid bilayer. From the EPR spectra obtained, using the formula for rapidly rotating probes, the rotation correlation time... 

Figure 1. Dose-response diagram for the effect of ichfan on micro viscosity of the erythrocyte (A), and of the cell of Ehrlich ascitic carcinoma (B). Probe I (light) (2,2,6,6-tetramethyl-4-capryloyl-oxypiperidin-l-oxyl) is localized in the surface layer of the membrane lipid bilayer Probe II (dark) (5,6-benzo-2,2,6,6-tetramethyl-l,2.3,4-tetrahydro-y-carbolin-3-oxyl) in the deep near-protein sites of lipids.

Evidence of the sp/ro-indolenine mechanism also comes from the cyclization of certain a-aryl tryptamines with aromatic aldehydes. In the case of aryl substiments that are particularly electrrMi-rich (3,4-dimethoxy 3,4-methylenedioxy), isomeric tetrahydro-y-carbolines resulting from the competing migration of the electron-rich benzyl group predominate in a ratio of about 4 1 [319]. 

A-Alkylation of amides and amines and dehydrative -alkylation of secondary alcohols and a-alkylation of methyl ketones " have been carried out by an activation of alcohols by aerobic oxidation to aldehydes, with copper(II) acetate as the only catalyst. A relay race process rather than the conventional borrowing hydrogen-type mechanisms has been proposed for the aerobic C-alkylation reactions, based on results of mechanistic studies. A Winterfeldt oxidation of substituted 1,2,3,4-tetrahydro-y-carboline derivatives provides a convenient and efiflcient method for the synthesis of the corresponding dihydropyrrolo[3,2-fc]quinolone derivatives in moderate to excellent yields. The generality and substrate scope of this aerobic oxidation have been explored and a possible reaction mechanism has been proposed. Direct oxidative synthesis of amides from acetylenes and secondary amines by using oxygen as an oxidant has been developed in which l,8-diazabicyclo[5.4.0]undec-7-ene was used as the key additive and copper(I) bromide as the catalyst. It has been postulated that initially formed copper(I) acetylide plays an important role in the oxidative process. Furthermore, it has been postulated that an ct-aminovinylcopper(I) complex, the anti-Markovnikov hydroamination product of copper acetylide, is involved in the reported reaction system. Copper(I) bromide... 

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