Synthesis of New 1,2,3,4-Tetrahydroisoquinoline Derivatives. 2-(2,3,3-Trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)anilines

A four-step procedure has been developed for the synthesis of new 2-(2,3,3-trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)anilines by acylation of 2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)anilines at the amino group with isobutyryl chloride, reduction of the endocyclic C=N bond in N-[2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)phenyl]isobutyramides, N-alkylation of N-[2-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenyl]isobutyramides to N-[2-(2,3,3-trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenyl]isobutyramides, and acid hydrolysis of the latter.     

Direct heterocyclization of tetrahydroisoquinolin-1-ylideneacetic acids by the action of 5-arylfuran-2,3-diones

Aroylketenes generated in situ by thermolysis of 6-aryl-2,2-dimethyl-4H-1,3-dioxin-4-ones reacted with 3,3-dialkyl-1-methyl-3,4-dihydroisoquinolines to give (1Z,3Z)-4-aryl-4-hydroxy-1-[3,3-dialkyl-3,4-dihydroisoquinolin-1(2H)-ylidene]but-3-en-4-ones. The crystalline and molecular structure of (1Z,3Z)-4-hydroxy-1-[6,7-dimethoxy-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]-4-phenylbut-3-en-2-one was studied by X-ray diffraction.     

Five-membered 2,3-dioxo heterocycles: LXIX. Direct heterocyclization of [3,4-dihydroisoquinolin-1(2H)-ylidene]-acetamides with 5-arylfuran-2,3-diones. Crystalline and molecular structure of (3E,5Z)-3-[3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]-5-(2-oxo-2-phenylethylidene)pyrrolidine-2,4-dione

5-Arylfuran-2,3-diones react with (Z)-2-[3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]acetamides to give (3E,5Z)-5-(2-aryl-2-oxoethylidene)-3-[3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]-pyrrolidine-2,4-diones. The crystalline and molecular structures of one of the products were determined by X-ray analysis.     

Reaction of 1-hydrazino-3,3-dimethyl-3,4-dihydroisoquinoline with ethyl acetoacetate. The crystal structure and IR spectra of ethyl 3-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolylidenehydrazono)-2-oxobutanoate

The reaction of 1-hydrazino-3,3-dimethyl-3,4-dihydroisoquinoline with ethyl acetoacetate afforded ethyl 3-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolylidenehydrazono)-2-oxobutanoate. The crystal structure of the title compound was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 966–970, May, 1999.     

Heterocyclization of 1,1-dicyano-2-(trifluoromethyl)ethylenes with 1,3,3-trimethyl-3,4-dihydroisoquinoline and its derivatives

1,3,3-Trimethyl-3,4-dihydroisoquinolines react with 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene to give 4-amino-6,6-dimethyl-2,2-bis(trifluoromethyl)-3-cyano-6,7-dihydro-2H-benzo[a]quinolizines. The reaction of 3,3-dimethyl-1-cyanomethylidene-1,2,3,4-tetrahydroisoquinoline and the methyl ester of 3,3-dicyano-2-(trifluoromethyl)acrylic acid leads to 5,5-dimethyl-3-oxo-2-(trifluoromethyl)-2-(dicyanomethyl)-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1888–1892, August, 1992.     

Reaction of dichlorocarbene with substituted 3,4-dihydroisoquinolines and 1-methylene-1,2,3,4-tetrahydroisoquinolines

Reaction of dichlorocarbene with 3,3-dialkyl-3,4-dihydroisoquinolines results in the formation of gemdichloroazirino[2,1-a]isoquinolines, which are in turn converted to 3-benzazepinones upon hydrolysis. Reaction of dichlorocarbene with the ethyl ester or amide of (3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-ylidene)acetic acid is accompanied by rearrangement of the intermediate carbene adducts at the enamine C=C bond and results in the formation of a 1-azadiene, 3-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)-3-chloroacrylic acid ethyl ester, and a spirolactam, 3,3-dimethyl-3-chlorospiro[1,2,3,4-tetrahydroisoquinoline-1,2-pyrrole]-5(2H)-one, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1091, August, 1990.     

Azo Coupling of Enamino Amides of the 3,3-Dimethyl-1,2,3,4-tetrahydroisoquinoline Series with Arenediazonium Salts

Russian Journal of Organic Chemistry - The azo coupling of arenediazonium chlorides with (Z)-2-(3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene)-N-(4-methylphenyl)acetamide afforded...     

Synthesis of Monooximes of 3,3-Dialkyl-3,4-dihydro-1-isoquinolyl Aryl Ketones and Diketones

1-Aroylmethyl-3,3-dialkyl-3,4-dihydroisoquinolines were synthesized by the Ritter reaction. The nitrosylation of these isoquinoline derivatives proceeds smoothly at the -enamine carbon atom to give monooximes of 3,3-dialkyl-3,4-dihydro-1-isoquinolyl aryl diketones. Loss of an acetyl group occurs in the nitrosylation of 1-(-acetylbenzyl)-3,3-dimethyl-3,4-dihydroisoquinoline.     

Facile synthesis of 3,4-dihydro-4,4-dimethyl-2H-pyran-2-one via palladium catalyzed terminal oxidation of 3,3-dimethyl-4-pentenoates

Selective terminal oxidation of 3,3-dimethyl-4-pentenoates does occur under chloride-free Wacker conditions [Pd(OAc)₂/O₂] in AcOH to give 5-acetoxy-3,3-dimethyl-4-pentenoates (7) and their analogues (2, 8) in good yields. Successive cyclization of 7 and 8 at vapor phase pyrolysis on SiO₂ affords 3,4-dihydro-4,4-dimethyl-2H-pyran-2-one (1).     

Synthesis of Pyrimido[6,1-a]isoquinolines by the Reaction of Thriethyl Orthoformate with Enamines of 3,3-dialkyl-1,2,3,4-tetrahydroisoquinoline series

Russian Journal of Organic Chemistry - Boiling (Z)-2-[3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]acetamides in AcOEt/Ac2O leads involves annelation of the pyrimidine ring to form...     

Some Transformations of 2-(Chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[<Emphasis Type="Italic">h</Emphasis>]quinazolin-4(3<Emphasis Type="Italic">H</Emphasis>)-one

The condensation of 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carbonitrile with chloroacetyl chloride afforded chloro-N-(2-cyano-3,3-dimethyl-3,4-dihydronaphthalen-1-yl)acetamide which underwent cyclization to 2-(chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin-4(3H)-one. The latter reacted with various nucleophiles (alkali metal alkoxides, piperazine, 2-sulfanylethanol) to give 2-(alkoxymethyl)-, 2-(piperazin-1-ylmethyl)-, and 2-{[(2-hydroxyethyl)sulfanyl]methyl}-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin- 4(3H)-ones. The condensation of 2-(chloromethyl)benzo[h]quinazoline with 2-thioxo derivatives of quinazoline and benzo[h]quinazolines led to the formation of bis-quinazolines in which 5,5-dimethyl-5,6- dihydrobenzo[h]quinazolin-4(3H)-one fragment is linked to quinazoline or benzo[h]quinazoline system through a CH₂S bridge.     

Interaction of 1-methylthio-3,3-dimethyl-3,4-dihydroisoquinoline with Β-dicarboxylic acids, Β-dicarbonyl compounds,and their analogs

1-Methylthio-3,3-dimethyl-3,4-dihydroisoquinoline interacts as an electrophile with -dicarbonyl compounds and their analogs to form products in which one or two hydrogen atoms of the -carbonyl compound are replaced by a 3,3-dimethy 1-3,4-dihydroisoquinolyl or 3,3-dimethyl-1,2,3,4-tetrahydroisoquinolylidene fragment.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1651–1654, December 1992.     

Reactions of 2,3-dioxopyrrolo[2,1-<Emphasis Type="Italic">a</Emphasis>]isoquinolinecarboxylic acid esters and amides with nitrogen-centered nucleophiles

Reactions of ethyl 2,3-dioxopyrrolo[2,1-a]isoquinoline-1-carboxylates with active nitrogen-centered nucleophiles (phenylhydrazine, hydroxylamine, and benzylamine) involve opening of the pyrrole ring with formation of 2-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-ylidene)-N′¹,N′⁴-diphenyl-3-(2-phenylhydrazono) succinohydrazide, 5-(6,7-dimethoxy-3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-ylidene)-2,3,4,5-tetrahydro-1H-1,2-oxazine-3,4,6-trione, and ethyl 4-benzylamino-2-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-ylidene)-3,4-dioxobutanoate, respectively. Cyclic amides derived from 5,5-dimethyl-2,3-dioxo-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline-1-carboxylic acid react with benzylamine in a similar way. Reactions of the title compounds with weaker nucleophiles, such as semicarbazide and thiosemicarbazide, are not accompanied by opening of the pyrrole ring, and the products are the corresponding semicarbazones and thiosemicarbazones at the C²=O carbonyl group.     

Reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with polyhaloalkanonitriles

The reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with halogenated nitriles afford -aminovinylimines, which undergo acid hydrolysis to form 1-(polyhaloacylmethylene)-3,3-dimethyl-3,4-dihydroisoquinolines.     

Oxiranes in the Ritter Reaction. Synthesis of 6,7- and 5,8-Dimethoxy-3,3-dialkyl-3,4-dihydroisoquinolines by a Tandem Alkylation-Cyclization Reaction

The interaction of 1,2- or 1,4-dimethoxybenzene with isobutylene oxide and nitriles RCN leads to 1-R-6,7- or 1-R-5,8-dimethoxy-3,3-dimethyl-3,4-dihydroisoquinolines. In the case of 1,2-dimethoxybenzene and cyclohexene oxide the similar reaction is accompanied by rearrangement and 1-R-3,3-tetramethylene-3,4-dihydroisoquinolines are formed in low yield. On using cyanoacetic acid ester and any oxide derivatives of tetrahydroisoquinolylideneacetic acid are formed.     

Investigation of paths for the synthesis of 5,5-dialkyl-3-perfluoroalkyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinolines

Substituted 3-trifluoromethyl-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinolines were obtained by the reaction of substituted 1-methylthio-3,4-dihydroisoquinolines with hydrazine hydrate and trifluoroacetic acid. The corresponding 3-perfluoroalkyl derivatives are formed in the course of dehydration of 2-(3,3-dimethyl-3,4-dihydro-1-isoquinolyl)hydrazides of perfluorocarboxylic acids.Institute of Technical Chemistry, Ural Branch, Russian Academy of Sciences, Perm. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 380–386, March, 2000.     

Synthesis of 2,3,9,10,16,17,23,24-Octaalkynylphthalocyanines and the Effects of Concentration and Temperature on Their (1)H NMR Spectra

The syntheses of 3,4- and 4,5-diiodophthalonitriles are described. Coupling of the latter compound with Pd(PPh(3))(2)Cl(2) and 1-octyne, 1-heptyne, 1-hexyne, 1-pentyne, and 3,3-dimethyl-1-butyne gave a series of 4,5-dialkynylphthalonitriles. Hydrogenation of 4,5-bis(1-pentynyl)phthalonitrile and 4,5-bis(3,3-dimethyl-1-butynyl)phthalonitrile gave 4,5-dipentylphthalonitrile and 4,5-bis(3,3-dimethylbutyl)phthalonitriles. Condensation of the dialkynylphthalonitriles with lithium 1-pentoxide in 1-pentanol gave 2,3,9,10,16,17,23,24-octaalkynylphthalocyanines, while intervention of the intermediate dilithium phthalocyanines with zinc acetate gave the related zinc(II) phthalocyanines. (1)H NMR spectroscopy of these octaalkynylphthalocyanines exhibited large chemical shifts (1-2 ppm) of the internal and aromatic protons at concentrations ranging from 10(-)(2) to 10(-)(5) M and at temperatures from 27 to 147 degrees C. The effects of aggregation phenomena are discussed. The importance of reporting concentration and temperature values for NMR spectra of phthalocyanines is stressed.     

Synthesis of 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione from mucobromic acid

Palladium-catalyzed cross-coupling between 2,5-dimethyl-3-thienylboronic and mucobromic acids under phase transfer catalysis (PTC) conditions gave the expected 3,4-bis(2,5-dimethyl-3-thienyl)-5-hydroxyfuran-2-one in 32% yield. The by-product was 2,2’,5,5’-tetramethyl-3,3’-bithiophene. The oxidation of the obtained hemiacylal with potassium permanganate under PTC conditions afforded 3,4-bis(2,5-dimethyl-3-thienyl)furan-2,5-dione in high yield.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2238–2240, October, 2004.     

Five-membered 2,3-dioxo heterocycles: LVII. Recyclization of 3-pivaloylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones by the action of o-phenylenediamine. Crystalline and molecular structure of 3-[3,3-dimethyl-2-oxo-1-(3-oxo-3,4-dihydroquinoxalin-2-yl)butyl]-1-phenylquinoxalin-2(1H)-one

3-[(Z)-3,3-Dimethyl-2-oxobutylidene]-3,4-dihydroquinoxalin-2(1H)-one and its 1-phenyl-substituted analog reacted with oxalyl chloride to give the corresponding 3-pivaloylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones. Reactions of the latter with o-phenylenediamine led to the formation of 3,3′-(3,3-dimethyl-2-oxobutane-1,1-diyl)di[quinoxalin-2(1H)-ones]. Original Russian Text ? K.S. Bozdyreva, Z.G. Aliev, A.N. Maslivets. 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 4, pp. 612–616. For communication LVI, see [1].     

Conformations of the triplet state of aromatic olefins. Observation of the transoid triplet states of 3,3-dimethyl-1-(2-naphthyl)-1-butene and 3,4-dihydrophenanthrene as a rigid planar triplet model

The observed triplet—triplet absorption of 3,3-dimethyl-1-(2-naphthyl)-1-butene is assigned to the planar transoid geometry (³t*) from its spectral similarity to the 3,4-dihydrophenanthrene triplet, a rigid planar model, as well as from the measured rate constants for its quenching by azulene and oxygen. The results are in contrast the 1,2-diarylethylene triplets which favor the perpendicularly twisted geometry (³p*).