Zur Darstellung von Pyrazino[3,2,1-j,k]carbazol-Derivaten

Synthesis of Pyrazino[3,2,1-j,k]carbazole Derivatives The synthesis of the tetrahydrocarbazolones 3a-g from the p-benzoquinones 6a/b and the 2-(aminomethylene)cyclopentanone derivatives 7 is reported as well as the cyclisation of the N-aminoacetonotrile derivative 3d to the title compound 8a.     

Synthese und Funktionalisierung chlorsubstituierter Bicyclo- und 8-Oxabicyclo[3,2,1]octa-2,6-dien-4-one

Synthesis and Functionalisation of Chlorinated Bicyclo- and 8-Oxabicyclo[3,2,1]octa-2,6-dien-4-ones We describe a simple synthesis of the bridged tropone derivatives 7a and 7b by acidic hydrolysis of the chlorinated bicyclooctadienes 4a and b and reaction of the hydrolysis products with trimethylsilylamines or (methylthio)trimethylsilane/AlCl₃. The procedure yields the novel vinylogous amides 9 and 10 and the thio esters 12 .     

Synthesis and pharmacological examination of hydrogenated 8-phenyl-1H-pyrazino-[3,2,1-jk]carbazoles

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 25, No. 2, pp. 27–29, February, 1991.     

Synthese und Eigenschaften von Thiopyrano[4,3,2-de]chinazolinen

Synthesis and Properties of Thiopyrano[4,3,2-de]quinazolines Starting from the 5-aminothiochromones 5 , the thiopyrano[4,3,2-de]quinazolines 11 and their S,S-dioxides 2 were prepared. In contrast to 2a , which was reduced by formamide to give 17 , formamide opened the thiopyranone ring of 7a to form the quinolone 20 .     

Synthese und Struktur von 1 H-Benzo[d]pyrido[2,1-b] thiazol-Derivaten

The reaction of dialkyl acetonedicarboxylates and o-aminothiophenol in boiling xylene yields 3-hydroxy-1-oxo-1 H-benzo-[d]pyrido[2,1-b]thiazole (I). The structure of I and its methyl and acetyl derivatives are deduced from their IR-and NMR-spectra.     

Synthese und Reduktion von Benzo [f] indol-4,9-dion-Derivaten

Synthesis and Reduction of Benzo [f]indole-4,9-diones The title compounds were synthesized in acceptable yields from the known precursor 1 . Reduction of 3 with zinc in acetic acid yields 4 -hydroxybenzindoles 6 instead of the hydroquinone derivatives 5 . The course of the reaction is discussed.     

Einfache Synthese von Isochino[2,3-c][2,3]benzoxazepinon und -[2,3]benzodiazepinonen sowie ihrer Vorstufen

Facile Synthesis of Isoquino[2,3-c][2,3]benzoxazepinone and -[2,3]benzodiazepinones and Their Precursors The isoquinolones 8a , 11a and 17 can be prepared easily from 6 , ammonia and hydroxylamine or hydrazine ( 14a ). By dehydration the isoquino-fused isoquinolone 9 , 2,3-benzoxazepinone 13 and 2,3-benzodiazepinone 16a are obtained. Reactions of the dicarboxylic acid 4 with the hydrazines 14a - c afford the 2,3-benzodiazepines 15a , b and 21 . The oxime 10 rearranges thermally, probably via 13 , to form the phthalide 12 .     

Synthese und pharmakologische Prüfung von 2- und 3-substituierten Pyrano[2,3-b]indolonen

Synthesis and Pharmacological Test of 2- and 3-Substituted Pyrano[2,3-b]indolones . The condensation of oxindole (3a) with ethyl 2-methylacetoacetate (6b) leads to the propionyloxindole 4 . With the acetal esters 6f, 6g and 6h and the cyclic β-ketoesters 12, 13 and 14 the reaction results in the 3-acyloxindoles 7f, 7c , and 7d or 7h and 15a, 15b, 15c . These can be cyclised to the 2- and 3-substituted pyrano[2,3-b]indolones 16a–16c and 17a–17c .     

Synthese von 5H-Pyrido[2,3-c]-2-benzazepinen

Synthesis of 5H-Pyrido[2,3-c]-2-benzazepines The title compounds can be obtained by two differend ways: Ring closure of 2-benzazepine enaminonitrile 1 and the C₂-building blocks 2, 7 and 8 gives rise to the title compounds 6, 9 and 10 . - The second way starts with Wolff-Kishner-reduction of the 2-amino-3-benzoylpyridines 16a,b to the 2-amino-3-benzylpyridines 18a,b . Benzoylation of 18a,b leads to the dibenzoylated compounds 20 and 21 , respectively, which can be transformed to the monobenzoylated pyridines 22 resp. 23 . Applying the Bischler-Napieralski-reaction on 22a,b and 23a,b leads to the 5H-pyrido[2,3-c]-2-benzazepines 24a,b and 25a,b . By means of ¹H-, ¹³C- and ¹⁵N-NMR-data it is demonstrated that ethyl benzoylcyanacetimidate ( 12a ) exists as benzoylketene-O,N-acetal 12a AE .     

Synthese und Reaktionen von Disulfoniumsalzen in der Bicyclo[2.2.1]heptenreihe

Synthesis and Reactions of Disulfonium Salts in the Bicyclo[2.2.l]heptene Series Nucleophilic replacement of the vinylic chlorine atoms in 2 by the methanethiolate anion affords the bis(methylthio) compound 4 , which can be alkylated by trimethyloxonium tetrafluoroborate to yield the bissulfonium salt. With nucleophiles, such as amines or water, dealkylation of 8 to yield 4 or 10 takes place, whereas treatment with sodium methoxide or sodium hydroxide leads to 11 or the ylide 9 . On heating, 9 shows novel rearrangements which yield 12 or 14 depending on the reaction conditions.     

Intramolekulare Aromatenalkylierungen, 25.Mitt. Zur Synthese von Hexahydro-7H-naphtho[1,8-fg]chinolinen und -isochinolinen

Intramolecular Alkylations of Aromatic Compounds, XXV: On the Synthesis of Hexahydro-7H-naphtho[1,8-fg]quinolines and -isoquinolines The carbinol 7 prepared from 5 and 6 is oxidised to yield the ketone 9 , while 16 and 21 are obtained immediately from 14 by Grignard reaction. The ketones 9 , 16 , and 21 are reduced to give the methylene compounds 10 , 17 , and 22 . The hydrogenolysis of 7 or its methyl ether 8 fails to give 10 . Treatment of 10 , 17 , and 22 with methyliodide furnishes the methoiodides 11 , 18 , and 23 , followed by NaBH₄ reduction to yield the tetrahydropyridines 12 , 19 , and 24 . Only 24 undergoes cyclisation to form 26 regioselectively.     

Synthese und Alkylierung von 10H-Pyrimido[5,4-b][1,4]benzothiazinen

Synthesis and Alkylation of 10H-Pyrimido[5,4-b][1,4]benzothiazines 10H-Pyrimido[5,4-b][1,4]benzothiazines 8 were prepared by condensation of barbituric acids 5 with 2-aminothiophenol (7) in DMSO via the ylide 6 . Compound 8 was characterized as a 1,5-dihydro system similar to the thia-isoalloxazines 1b . The structures of the alkyl derivatives isolated from a complex mixture were established by UV/VIS, ¹H-NMR, IR and ESR spectroscopy. They are discussed with regard to the alkylation of pyrimidobenzothiazines which carry substituents at N-10.     

Synthese von Pyrrolo[2,3-d]pyrimidinen

Synthesis of Pyrrolo[2,3-d]pyrimidines A simple synthesis of pyrrolo[2,3-d]pyrimidines is described. Basic materials are 2-amino-3-cyano-pyrroles. The yields are good or excellent.     

Synthese und Eigenschaften von 1- und 10-Amino-11H-5,6-dihydrodibenz[b,e]azepin-6,11-dionen

Syntheses and Properties of 1-and 10-Amino-11 H-5,6-dihydrodibenz[b,e]azepine-6,1l-diones A method is described for the separation of the mixture of the dihydrodibenz[b,e]azepinediones 1 and 3 resulting from a Schmidt reaction of 1-amino-anthraquinones. Compounds 1 und 3 , as well as the derived enamines 14a , 14b and 19 can be reduced to the alcohols 7b , 11 , 17a and 17b which in turn can be converted to the lactones 9a , 9c , 12 and 16a and to the oxazine derivative 18 .     

Verbesserte Synthese von methyl- und phenylsubstituierten Pyrido[2,3-d]pyrimidin-2,4-diaminen

Improved Synthesis of Methyl- and Phenyl-substituted Pyrido-[2,3-d]pyrimidine-2,4-diamines The title compounds 4b-g, 10a,b and 13 can be prepared in improved yields by “cyclocondensation” of the 1,3-biselectrophiles la-e, 5b,f,g, 7b,d, 8a,b , and 12 with 2,4,6-triaminopyrimidine ( 2 ).     

Synthese von basisch substituierten 5H-Pyrimido[4,5-c]-2-benzazepinen

Synthesis of Basically Substituted 5H-Pyrimido[4,5-c]-2-benzazepines The potentially CNS-active title compounds 19a-c can be prepared by a nine step synthesis beginning with phthalaldehydic acid. Knoevenagel condensation of 5 with the acetonitriles 2a-g and subsequent reduction with NaBH₄ lead to the dihydrocinnamic acid nitriles 3 . Only 3a can be cyclized to the 2-benzazepinnitriles 9a,b . Ammonolysis of 9a yields the enaminonitrile 10 , which is reacted with the orthoesters 11a-c to the imidic acid esters 12a-c . Ammonolysis leads to the tricycles 16a,b . After transformation of the lactam group in 16 to an imidoyl chloride 17 , aminolysis with the amines 18a-c provides the title compounds 19a-c .     

Eine bequeme Synthese von 2-Aryl-2-vinyl-[1,3]-dioxolanen und -dioxanen

A Convenient Synthesis of 2-Aryl-2-vinyl-[1,3]-dioxolanes and -dioxanes Cyclocondensation of γ-aryl-γ-oxosulfones 1 with 1,2- or 1,3-dioles 2 and 3 leads to 2-aryl-2-sulfonylethyl-[1,3]-dioxolanes 4 , and -dioxanes 5 , respectively. In the presence of potassium tert-butoxid 4 and 5 eliminate sulfinic acid yielding the title compounds 6 and 7 .