First synthesis of a series of core-modified tetrabenzoporphyrins

Successful synthesis of a series of highly conjugated porphyrin analogues, including thia-, dithia- and oxathia-tetrabenzoporphyrins, and their optical properties are reported.     

First example of Diels-Alder reaction in the 2,3,4,4a-tetrahydroquinoline series. Synthesis of hydrogenated 5,8-ethanoquinolines

Diels-Alder reactions in the 2,3,4,4a-tetrahydroquinolines series were studied for the first time. It was shown that these dienes demonstrate only moderate reactivity. [4+2] Cycloaddition occurs stereo- and regioselectively only for alkenes bearing an electron-withdrawing group (acrylonitrile, maleic anhydride, dimethyl acetylene dicarboxylate, methyl propiolate). In this case, endo-Diels-Alder adducts, spiroannelated 5,8-ethanoquinolines, are formed in a high yield. Cyclopentadiene, being a highly reactive diene component, reacts with 2,3,4,4a-tetrahydroquinolines as the dienophile. Electron-rich unsaturated compounds (N-vinylpyrrolidone, vinylethyl ether, phenylacetylene) are inert to this cycloaddition reaction.     

Synthesis of heterosteroids. First synthesis of oxa steroid from cholic acid

We wish to report here a new and efficient partial synthesis of 3-oxa-5β-steroid, the first oxa steroid synthesized from cholic acid.     

First synthesis of a selenazepane

The first synthesis of perhydroselenazepane derivatives by the reaction of aryl isoselenocyanates with 5-chlorobutylamine in the presence of triethylamine in DMF as a one-pot procedure is described.     

Organometallic synthesis in the furazan series. 2. Furazanylethanes

The reactions of Li derivatives of methylfurazans with electrophilic reagents and oxidants were investigated. A series of functionalized furazanylethane derivatives were prepared.     

Synthesis in a series of quinoline derivatives

Monomeric substances, 8-methacryloxyquinolines were synthesized with the object of obtaining preparations with prolonged action.For part V, see [1].     

Synthesis of three marine natural sesterterpenolides from methyl isoanticopalate. First enantioselective synthesis of luffolide

[Reaction: see text]. The synthesis of three marine sponge metabolites, luffolide (4), 5, and 6, are described for the first time, establishing the absolute configuration of these compounds. The key intermediate, aldehyde 17, was obtained from methyl isoanticopalate, 11. The addition of 3-furyllithium to 17 and subsequent photochemical oxidation give the gamma-hydroxybutenolide 5 and its epimer at C-16. Sesterterpenolide 6 is obtained by dehydration of 5. From the key aldehyde 17, luffolide (4) was obtained in six steps.     

Synthesis in the phenothiazine series

The corresponding amines were obtained by reduction of 1-nitro-3-bromophenothiazine and 2-bromo-4-nitrophenothiazine. 1-Amino-3-bromophenothiazine reacts with formic acid to give 4-bromoimidazo[4,5,1-k, l ]phenothiazine and with carbon disulfide to give 4-bromo-1,2-dihydroimidazo [4,5,1-k, l ]phenothiazine-1-thione. 4-Aminophenothiazine reacts with sulfur and carbon disulfide to give 2, 3-dihydrothiazolo[5,4-c]phenothiazine-2-thione.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 202–203, February, 1974.     

Synthesis in the phenothiazine series

Ketovinylaminophenylthiazines, which are cyclized in acidic media to dimethylpyridophenylthiazines — new four-ring compounds — were obtained by the action of acetylacetone on aminophenylthiazines.See [1] for communication XXXVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 50–54, January, 1975.     

Synthesis in the phenothiazine series

1,2-Dihydroimidazo[4,5,1-n,m]phenothiazine-1-thione (III) was synthesized by the reaction of 1-aminophenothiazine (II) with sulfur and carbon disulfide or potassium ethylxanthogenate. The oxidation of III with hydrogen peroxide in alkali and acid media leads to imidazo-[4,5,1-n,m]phenothiazine (I) and imidazo[4,5,1-n,m]phenothiazine 6,6-dioxide (VI), respectively. Several S-alkyl and S-aralkyl derivatives of in (IVa-d) were obtained by the action of alkyl and aralkyl halides; the oxidation of IVa-d in acetic acid gave 1,2-dihydroimidazo-[4,5,1-n,m]-1-phenothiazone 6,6-dioxide (VII).See [1] for communication XXXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 770–772, June, 1971.     

Synthesis in the phenothiazine series

1-Bromophenothiazine (I) and 1,3-dibromophenothiazine (II) have been synthesized by the intramolecular rearrangement of 2-acetylaminophenyl 2-bromo-6-nitrophenyl sulfide (III) and 2-acetylaminophenyl 2,4-dibromo-6-nitrophenyl sulfide (VIII) and the subsequent cyclization of resulting N-acetyl-2-bromo-2-mercapto-6-nitrodiphenylamine (IV) and N-acetyl-2,4-dibromo-2-mercapto-2-nitrodiphenylamine (IX), followed by saponification of the acetyl groups of the latter, respectively.For Communication XXIV see [6].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1041–1044, August, 1970.     

Synthesis in the phenothiazine series

Quaternary salts of imidazo[4,5,1-k,l]phenothiazine were reduced with potassium borohydride to 1,2-dihydro-2-methylimidazo[4,5,1-k,l]phenothiazine, which was converted to 1,2 dihydro-2-methylimidazo[4,5,1-k,l]phenothiazine-1-thione and 1-methylamino-10-formylphenothiazine. The latter was hydrolyzed to 1-methylaminophenothiazine, which was also obtained by reduction of methyl phenothiazine-1-carbamate. The PMR and IR spectra of some of the derivatives are discussed.See [1] for communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 372–374, March, 1974.     

Synthesis in the phenothiazine series

The UV spectra of 18 phenothiazine derivatives and seven diphenylamine derivatives having similar substituents in the corresponding positions of the benzene ring are presented. The interrelationship between the structure and the character of absorption in the UV region is discussed.For Communication XXV see [7].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1333–1336, October, 1970.     

Synthesis in the phenothiazine series

A method was developed for the preparation of 3,7-diamino-10-acetylphenothiazine 5-oxide by the reduction of 3,7-dinitro-10-acetylphenothiazine 5-oxide with hydrazine hydrate in the presence of a nickel catalyst.See [1] for communication XXXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 325–327, March, 1972.     

Synthesis of the First

A "true" allenophane with several rings and allenic bridges was synthesized. The key step in the preparation of 1 was the cyclization to a 28-membered macrocycle (52 % yield) starting from a linear molecule, which already contains three of the four allene units.     

Organometallic synthesis in the furazan series. 3. Silyl derivatives of methylfurazans

The reactions of (lithiomethyl)furazans with chlorosilanes were investigated and a number of silyl derivatives of methylfurazans were prepared. The reactivity of these compounds was studied.