Synthesis of enamine derivatives of 3,4-dihydroisoquinoline

Shklyaev, V. S.; Aleksandrov, B. B.; Legotkina, G. I.; Вахрин, М. И.; Gavrilov, M. S.; Михайловский, А. Г.

doi:10.1007/bf00515370

Cited by 22 publications

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“…Three-component condensation using 3,4-dimethoxybenzyl cyanide as the major reaction component led to the adduct of two molecules of the above nitrile and isobutyraldehyde (10), the Bayer reaction product (11), and ∼15% isoquinoline (12), the latter containing a keto-group at C1 (Scheme 5). SCHEME 2 Similar results were obtained for ortho-xylol, with some of the product 13 being formed in the reaction (Scheme 6).…”

Section: Resultsmentioning

confidence: 99%

A new approach to synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives

Shklyaev

Yeltsov

Rozhkova

et al. 2004

Heteroatom Chemistry

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Section: Resultsmentioning

confidence: 99%

A new approach to synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives

Shklyaev

Yeltsov

Rozhkova

et al. 2004

Heteroatom Chemistry

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“…The synthesis of the initial enamines 1, 3, and 6 was described in [5][6][7], and the 3-bromoacetylcoumarins in [8,9]. A mixture of the respective enamine (10 mmol) in 2-propanol (30 ml) was boiled for 1 h (monitored by TLC) with 3-bromoacetylcoumarin (3.01 g, 12 mmol) or 3-bromoacetylbenzo[f]coumarin (3.61 g, 12 mmol) in the presence of Na 2 CO 3 (1.5 g).…”

Section: Methodsmentioning

confidence: 99%

Synthesis of 2-(3-coumarinyl)pyrrolo[2,1-a]isoquinoline derivatives by the chichibabin reaction

Kulikova

Сурикова

Михайловский

et al. 2011

Chem Heterocycl Comp

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Keywords: benzo[f]isoquinoline, benzo[f]coumarin, 3-bromoacetylcoumarin, enamines of the 3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline series, 2-(3-coumarinyl)-5,5-dimethyl-5,6-dihydropyrrolo[2,1-a]-isoquinolines, Chichibabin reaction.The classical method for the construction of the pyrrolo[2,1-a]isoquinoline system is the Chichibabin reaction, which involves the reaction of 1-methylisoquinoline with α-halo ketones [1, 2]. The successful use not only of heteroaromatic compounds such as pyridines and their benzo analogs but also of cyclic enamine derivatives in this reaction is well known [2,3]. Here 3-bromoacetylcoumarins are also worthy of attention as α-halo ketones in so far as the formation of a system consisting of two independent heterocyclic fragmentspyrrolo[2,1-a]isoquinoline and coumarin -has been proposed in this case. Structures of such a type are practically unknown in the literature. The aim of the present work was to investigate the possibilities of annelation of the pyrrole ring depending on the structure of the initial reagents.The investigations showed that the reaction of the isoquinoline 1 with 3-bromoacetylcoumarin takes place readily with boiling in 2-propanol in the presence of Na 2 CO 3 , with the formation of compound 2. If compounds 3a,b are used as initial enamines the reaction products are compounds 4a,b. The corresponding bromoacetyl derivative of benzo[f]coumarin gives compound 5a in reaction with the enamine 1 and the amide 5b in reaction with the enamino amide 3b. In reaction with 3-bromoacetylcoumarin the benzo[f]isoquinoline derivative 6 forms the tetracyclic system 7. The obtained coumarin derivatives 2, 4, 5, and 7 (Table 1) are yellow crystalline substances.In the 1 H NMR spectra of the synthesized compounds (Table 2), in contrast to the spectra of the initial enamines, there are singlets for the pyrrole ring (6.28-7.12 ppm), the shift of which depends on the substituent at position 1 of the pyrrolo[2,1-a]isoquinoline system. All the spectra contain singlets for the HC= group of the coumarin ring (7.80-8.56 ppm) [4].

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“…The starting materials for the synthesis of compounds 2, 3 are described in [6,13,14], and of substances 5, 6 in [15]. Drotaverine base was isolated from tablets with a suitable expiry date, mp 58-60°C, its purity was checked by TLC.…”

Section: Methodsmentioning

confidence: 99%

“…In the given examples, both bases, in the molecules of which the structure of the enamine is already fixed, and compounds in the imino form, enter into this reaction. The latter is characteristic for derivatives of 1-alkylisoquinoline [6,7], the alkyl residue in the structure of which, unlike carbonyl or just withdrawing groups, does not aid stabilization of the enamine form. Consequently our aim is the study of the conditions of carrying out and the structures of the products of the named reaction in the presence of an alkyl residue at position 1 of the isoquinoline ring.…”

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confidence: 98%

Enamines of the 1,2,3,4-tetrahydroiso-quinoline series in the Chichibabin synthesis of pyrrolo[2,1-a]isoquinolines and in reaction with oxalyl chloride

Polygalova

Михайловский

Vikhareva

et al. 2007

Chem Heterocycl Compd

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Pyrrolo[2,1-a]isoquinolines are used widely in organic synthesis, medicine, and other areas [1]. The classical method of design the pyrrolo[2,1-a]isoquinoline system is the interaction of 1-alkylisoquinolines with α-halo ketones (the Chichibabin reaction) [1,2]. It is known [3] that on cyclization with the formation of condensed systems a determining role is played by the radicals in position 3 of the isoquinoline ring. The aim of the present work is an investigation of the potentialities of this reaction in the presence of two methyl groups in position 3 and also of a different structure for the enamine fragment.The reaction of enamines of the 1,2,3,4-tetrahydroisoquinoline series with oxalyl chloride has also been widely investigated [1,4,5]. In the given examples, both bases, in the molecules of which the structure of the enamine is already fixed, and compounds in the imino form, enter into this reaction. The latter is characteristic for derivatives of 1-alkylisoquinoline [6,7], the alkyl residue in the structure of which, unlike carbonyl or just withdrawing groups, does not aid stabilization of the enamine form. Consequently our aim is the study of the conditions of carrying out and the structures of the products of the named reaction in the presence of an alkyl residue at position 1 of the isoquinoline ring.The investigations showed that the reaction of enamines 1a-c with p-bromophenacyl bromide proceeds readily on boiling in alcohol in the presence of Na 2 CO 3 and compounds 2a-c are formed. On using drotaverine (no-spa) base as the initial enamine the reaction product is compound 2d. Enamino amides and enamino esters of the benzo[f]isoquinoline series, analogous in structure to compounds 1a-c, form the corresponding tetracyclic derivatives 3a-c in this reaction. __________________________________________________________________________________________ Perm State Pharmaceutical Academy,

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Synthesis of enamine derivatives of 3,4-dihydroisoquinoline

Cited by 22 publications

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A new approach to synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives

A new approach to synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives

Synthesis of 2-(3-coumarinyl)pyrrolo[2,1-a]isoquinoline derivatives by the chichibabin reaction

Enamines of the 1,2,3,4-tetrahydroiso-quinoline series in the Chichibabin synthesis of pyrrolo[2,1-a]isoquinolines and in reaction with oxalyl chloride

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