Synthesis of [3.n.3.n.]paracyclophane derivatives by cationic cyclization of styrene derivatives

Styrene derivatives (3c and 3d) were treated in dry benzene at 50 °C with a catalytic amount of CF₃SO₃H to afford [3.n.3.n]paracyclophane derivatives (4c and 4d) in 80 and 62% yields, respectively.     

Isothiazoles X. 3-alkoxyisothiazole derivatives

Halogenation of a number of 3-alkoxyisothiazoles, occurring exclusively in the 4-position, followed by cyanation led to various carboxylic acid, carboxamide and amine derivatives. Subsequent dealkylation provided 4-substituted-4-isothiazoIin-3-ones.     

Indole derivatives. XXIII. 3-Indolylethylene glycol

Lithium aluminum hydride reduction at room temperature of 3-hydroxyacetylindole and 3-benzyloxyacetylindole in tetrahydrofuran gives, respectively, 3-indolyethyleneglycol and 3-indolylethylene glycol monobenzylate. Sodium borohydride reduction of 3-hydroxyacetylindole gives tryptophol, and the reduction of 3-benzyloxyacetylindole gives tryptophol benzylate. Aluminum amalgam converts 3-hydroxyacetylindole and 3-benzyloxyacetylindole to 3-acetylindole.For part XXII see [1]     

Chemical properties of ylidene derivatives of azines. 3. Synthesis and reactions of ylidene derivatives of halopyrimidines

Some dihydropyrimidines have been obtained which contain a cyanoacetic ester or malononitrile residue and chlorine in positions, 2, 4, and 6. The reactions of these compounds with nucleophiles has been examined.For communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–969, July, 1986.     

Indole derivatives CII. C-acylation of 3-indolylacetonitrile

Claisen condensation of 3-indolylacetonitrile with diethyl carbonate, diethyl oxalate, and ethyl benzoate proceeds with acylation at the CH₂ group. Depending on the acylating agent, the reaction proceeds with retention or elimination of the N-acyl group.See [1] for communication CI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1502–1505, November, 1974.The authors thank K. F. Turchin for his assistance in the interpretation of the PMR spectra.     

Hexahydropyridazine derivatives. 3. Synthesis of hexahydro-4-pyridazinones

The reaction of azodicarboxylic acid esters with 2-methoxy- or 2-trimethylsilyloxy-1,3-butadienes gave a number of 1,2-bis(alkoxycarbonyl)-4-methoxy(trimethylsilyloxy)-1,2,3,6-tetrahydropyridazines, which were hydrolyzed to the corresponding hexahydro-4-pyridazinones.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 783–785, June, 1991.     

Pyrimidine derivatives XII. A convenient preparation of 6-formylpyrimidinedione and 2- and 3-formylpyridine derivatives from corresponding nitrooxymethyl derivatives

The convenient preparation of 6-fomylpyrimidinedione derivatives and 2- and 3-formylpyridine are described. Thus, 5-bromo-1,3-dimethyl- ( 1a ), 5-bromo-3-methyl-1-(2-nitrooxyethyl)- ( 1b ), and 5-bromo-3-methyl-1-(3-nitrooxypropyl)-2,4(1H,3H)-pyrimidine-dione ( 1c ) were converted to the corresponding 6-formyl compounds 2a, 2b , and 2c , respectively, in excellent yields by the reaction with triethylamine and 1,4-diazabicyclo[2.2.2]octane. These 6-formylpyrimidinedione derivatives are key intermediates for the preparation of 6-carbon-carbon substituted compounds, which are expected to be potential antitumor and antiviral agents. Similarly, 2-(and 3-)formylpyridine ( 9a (and 9b )) were obtained by the reaction of 2-(and 3)nitrooxymethylpyridine ( 8a (and 8b )) with 1,4-diazabicyclo[2.2.2]octane.     

Benzo[b]thiophene derivatives. VIII. Benzo[b]thiophene-3-earboxaldehyde and derivatives

A procedure for the preparation of benzo[b]thiophene-3-carboxaldehyde from 3-methyl-benzo[b]thiophene is reported. This aldehyde behaves as a typical reactive aromatic aldehyde with respect to oxidation, reduction, the mixed Cannizzaro reaction, reductive amination and acyloin and other condensation reactions.