THE PREPARATION OF 4-METHYL-1,3,4,5-TETRAHYDROPYRROLO[4,3,2-<i>de</i>]ISOQUINOLINE AND ITS CONVERSION INTO 3,4-DISUBSTITUTED INDOLES

Somei, Masanori; Yamada, Fumio; Maekawa, Tomoko; Kimata, Toshihiko; Kaneko, Chikara

doi:10.1246/cl.1978.1245

Cited by 10 publications

(4 citation statements)

References 9 publications

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“…The first strategy described in Scheme 1 worked well even in the case of the 1-substituted isoquinoline (X=CHR, Y=NMe). 7 Thus, the 1,2-dihydrocompound (12b) was obtained by the addition of acetone to the 1-position of 11. Subsequent above-mentioned Vilsmeyer reaction led 12b to 13b.…”

Section: -1 Strategy and Reality For Creating New Synthetic Methodsmentioning

confidence: 99%

Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Somei¹

2008

HETEROCYCLES

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Section: -1 Strategy and Reality For Creating New Synthetic Methodsmentioning

confidence: 99%

Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Somei¹

2008

HETEROCYCLES

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“…By modifying the experiment it was possible to produce macroquantities of these extremely difficultly obtainable indole derivatives. In another condensed derivative of isoquinoline -4-methyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de]-isoquinoline -opening of the hydrogenated quaternized six-membered ring with KCN in DMF leads not only to the formation of 4-isogramine but also to functionalization at position 3 of the indole ring [61]. …”

Section: Synthesis Of Indole Derivatives Containing a Dimethylaminomementioning

confidence: 99%

Methods for the Synthesis of Isogramines and Their Chemical Properties. (Review)

Семенов

Yurovskaya

2005

Chem Heterocycl Compd

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“…Since selective thallation of 2 was established as discussed above, we next examined direct introduction of a carbon side chain into the 7-position according to our thallationpalladation method.4) Thus, 2 was thallated and the resulting crude residue (3) was treated with methyl acrylate in the presence of a catalytic amount of palladium acetate (Pd(OAc)2) in DMF to afford methyl 3-(1-acetyl-2,3-dihydroindol-5-yl)acrylate (13) and methyl 3- (1-acety1-2,3-dihydroindol-7-ypacrylate (14) in 2% and 4% yields, respectively (Chart 3).…”

Section: Syntheses Of Various 7-substituted Indolesmentioning

confidence: 99%

The chemistry of indoles. XXXIX. A facile synthetic method for 7-substituted indoles.

Somei

Saida

Funamoto

et al. 1987

CHEMICAL & PHARMACEUTICAL BULLETIN

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A simple four-step synthetic method for 7-iodo-, 7-bromo-and 7-chloroindole was established with high overall yield starting from 2,3-dihydroindole. Several 7-substituted indoles carrying a carbon side chain and 7-methoxyindole were also synthesized. Keywordsthallation; 7-substituted indole; regioselective metalation; 7-iodoindole; 7-bromoindole; 7-chloroindole; 7-methoxyindole; methyl 3-(indol-7-yl)acrylate; 4-(indo1-7-y1)-2-methy1-3-buten-2-ol; Heck reaction For one possible approach to the construction of various types of structurally and biologically interesting indole alkaloids having a substituent at the 7-position,2) 7-halogenoindoles are required as common building blocks. However, little work has been done on their syntheses and consequently they are available only through a laborious multistep route) with poor overall yield. In our continuing studies on regioselective functionalization of indoles,4, 5) we have elaborated a facile and regioselective synthetic method for 7-halogenoindoles, as reported in the preliminary communication.6) In this report, we describe in detail these results and the syntheses of various 7-substituted indoles. Regioselective Syntheses of 7-HalogenoindolesIn the previous paper, we reported that the thallation-palladation method4) was a useful synthetic reaction for 4-substituted indoles with high regioselectivity. It was also shown that the regioselectivity was dramatically influenced by introduction of an extra substituent into the 2 or 3 position of the indole nucleus.5) Based on these results, we designed the strategy shown in Chart 1. If a suitable ligand (S) is introduced at the indole (or 2,3-dihydroindole) nitrogen, the S group can coordinate to a metal reagent (metal (M)-leaving group (L)) putting the metal close to the 7-position. Consequently, metallation would occur regioselectively at the carbon-7 making the carbon susceptible to various functionalizations.During examination of the feasibility of the strategy as planned, we soon recognized that thallation of 1-acy1-3-unsubstituted indoles with thallium tris-trifluoroacetate (TTFA) was unsuccessful because the compounds were quite sensitive to acids, and formed polymers.

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THE PREPARATION OF 4-METHYL-1,3,4,5-TETRAHYDROPYRROLO[4,3,2-de]ISOQUINOLINE AND ITS CONVERSION INTO 3,4-DISUBSTITUTED INDOLES

Abstract: Various 3,4-disubstituted indoles were prepared from 4-methyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de]isoquinoline which was obtained readily by the two novel synthetic routes starting from 2-methyl-5-nitroisoquinolinium iodide.

Cited by 10 publications

References 9 publications

Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Methods for the Synthesis of Isogramines and Their Chemical Properties. (Review)

The chemistry of indoles. XXXIX. A facile synthetic method for 7-substituted indoles.

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