New sesquiterpenes from Ferula ferulaeoides (Steud.) Korovin. VI. Isolation and identification of three new dihydrofuro[2,3-b]chromones

Three novel 2-prenyl-dihydrofurochromone-type sesquiterpenoid derivatives, 2,3-dihydro-7-hydroxy-2S*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadienyl]-furo[2,3-b]chromone, 2,3-dihydro-7-hydroxy-2S*,3R*-dimethyl-2-[4-methyl-5-(4-methyl-2-furyl)-3(E),7-pentenyl]-furo[2,3-b]chromone, and 2,3-dihydro-7-hydroxy-2R*,3R*-dimethyl-2-[4-methyl-5-(4-methyl-2-furyl)-3(E),7-pentenyl]-furo[2,3-b]chromone, were isolated from the roots of Ferula ferulaeoides. The structures were established by comprehensive spectral analysis. The biosynthetic pathway leading to these 2-prenyl-dihydrofurochromone-type sesquiterpenoids is proposed based on their structures.     

二芳杂环基乙烯的合成及其光致变色反应研究

本文报道了2,3-双 (1,2-二甲基-3-吲哚基)-2-丁烯 (DF1),2,3-双 (1,4-二苯基-2-甲基-3-吡咯基)-2-丁烯 (DF2), 2,3-双(1-对甲苯基-4-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF3), 2,3-双(1-对溴苯基-4-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF4) 和2,3-双 (1-对甲氧苯基-5-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF5) 的合成,以及它们的光致变色行为的研究。特别是DF1和DF5的光呈色和光消色过程进行了较为细致的研究。     

Reaction of 4,5-diamino-3-methyl-1-phenylpyrazole with 3-dimethylaminopropiophenones. Synthesis of new 4-aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines

New 4-Aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines were obtained from the reaction of 4,5-diamino-3-methyl-1-phenylpyrazole 1 with one equivalent of the 3-dimethylaminopropiophenones 2 in absolute ethanol. The structures of 4-aryl-6-methyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines 3 and 4-aryl-8-methyl-6-phenyl-2,3-dihydropyrazolo[4,3-b]diazepines 4 were determined by detailed nmr measurements.     

Thermal Valence Rearrangements of Heterocycles. Part 2. A new synthetic approach towards the indole ring system

A new synthetic approach towards the indole ring system is described. When dimethyl 1-methyl-2-oxa-1-aza-spiro[4.5]dec-3-ene-3,4-dicarboxylate ( 6 ) was refluxed in toluene, the previously known dimethyl 4,5,6,7-tetra-hydro-1-methyl-1H-indole-2,3-dicarboxylate ( 7 ) was obtained in 71% yield, via a 2,3-dihydroisoxazole-pyrrole rearrangement. After treatment with DDQ , the tetrahydro analogue 7 was converted to the corresponding dimethyl 1-methyl-1H-indole-2,3-dicarboxylate ( 8 ).     

Condensed Imidazo-1,2,4-azines. 31. Synthesis and Chemical Transformations of Substituted 1,2,4-Triazepino[2,3-a]benzimidazoles

By reaction of 1,2-diaminobenzimidazole with 1,3-diketones, acetoacetic ester and its derivatives, we have synthesized substituted 1,2,4-triazepino[2,3-a]benzimidazole and 5H-1,2,4-triazepino[2,3-a]benzimidazol-4-one. By reaction of 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazol-4-one with aromatic aldehydes or phenyldiazonium chloride, we have obtained 3-arylidene(phenylazo) derivatives of this compound, and by reaction with P₂S₅ we have obtained 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazole-4-thione. We have shown that when reacted with ammonia, primary or secondary amines, the latter forms 4-amino-substituted 2-methyl-1,2,4-triazepino[2,3-a]benzimidazole.     

On the reaction of 3-nitro-1,2-phenylenediamine with ethyl acetoacetate. Condensed dihydrodiazepinones

Condensation of 3-nitro-1,2-phenylenediamine with ethyl acetoacetate in boiling xylene gave two isomeric 2,3-dihydro-4-methyl-9-nitro- and 2,5-dihydro-4-methyl-6-nitro-1H-1,5-benzodiazepin-2-ones, the 9-nitro derivative thermal rearrangement product N-isopropenyl-4-nitrobenzimidazolone and a non cyclic acetoacetamide derivative. At room temperature these reactants afforded 2,3-dihydro-2-ethoxycarbonyl-methyl-2-methyl-4-nitrobenzimidazole.     

Sesquiterpenoid derivatives from Ferula ferulaeoides [correction of ferulioides]. V

Nine novel prenyl-dihydrofurocoumarin-type sesquiterpenoid derivatives, 2,3-dihydro-7-hydroxy-2R*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadienyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-hydroxy-2S*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadien-6-onyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-hydroxy-2S*,3R*-dimethyl-2-[4-methyl-5-(4-methyl-2-furyl)-3(E)-pentenyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-hydroxy-2R*,3R*-dimethyl-2-[4-methyl-5- (4-methyl-2-furyl)-3(E)-pentenyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-methoxy-2S*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadienyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-methoxy-2R*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadienyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-methoxy-2S*,3R*-dimethyl-2-[4,8-dimethyl-3(E),7-nonadien-6-onyl]-furo-[3,2-c]coumarin, and 2,3-dihydro-7-methoxy-2S*,3R*-dimethyl-2-[4-methyl-5-(4-methyl-2-furyl)-3(E)-pentenyl]-furo[3,2-c]coumarin, were isolated from the roots of Ferula ferulaeoides [corrected]. The structures were established by comprehensive spectral analysis. The biosynthetic pathway leading to these prenyl-furocoumarin-type sesquiterpenoids is proposed based on their structures.     

Synthesen von Heterocyclen, 149. Mitt.: Über Reaktionen mit cyclischen Oxalylverbindungen, 3. Mitt.

Propiophenone-N, N-diphenylhydrazone reacts with oxalyl chloride to give 1-diphenylamino-4-methyl-5-phenyl-2,3-dihydropyrrole-2,3-dione (1), which is isomerized at 130–140° yielding 2,3-dioxo-8, 8a-diphenyl-1, 2, 3, 3a, 8, 8a-hexahydro-3a-methyl-pyrrolo[2,3-b]indole (2). Butyrophenone-N, N-diphenylhydrazone and propiophenone-N-methyl-N-phenyl-hydrazone react in a similar way.     

Sur l'acylation des méthylfluorènes VI. Formylation du méthyl-2-fluorène et du méthyl-3-fluorène selon Rieche

The formylation of 2-methylfluorene and of 3-methylfluorene according Rieche yields 2-methyl-7-fluorene-carbaldehyde and 3-methyl-2-fluorenecarbaldehyde respectively. The constitution of the obtained aldehydes is proved by their conversion into the known 2,7-dimethyl-fluorene and 2,7-dimethyl-9-fluorenone, respectively into the known 2,3-dimethylfluorene and 2,3-dimethyl-9-fluorenone.     

Bromination and diazo-coupling of pyridinethiones; microwave assisted synthesis of isothiazolopyridine, pyridothiazine and pyridothiazepines

Isothiazolopyridines, pyridothiazines and pyridothiazepines are important compounds that possess valuable biological activities. This paper reports on the synthesis of these compounds using both conventional chemical methods and modern microwave techniques. 3-Bromo-6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide, 5-arylazo-6-hydroxy-4-methyl-2-thioxo-1,2-dihydropyridine-3-carboxamides, 3,5-bis-arylazo-6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-caboxamide, 4-methyl-2,3,6,7-tetra-hydroisothiazolo[5,4-b]-pyridine-3,6-dione, 2,2'-(methylene-bis-(sulfanediyl))bis(4-methyl-6-oxo-1,6-dihydropyridine-3-carboxamide), 2-hydroxy-5-methyl-4H-pyrido[3,2-e][1,3]-thiazine-4,7(8H)-dione and 2-arylmethylene-8-hydroxy-6-methyl-2,3,4,5-tetrahydropyrido-[3,2-f][1,4]thiazepine-3,5-diones have been prepared from 6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide. Some of these compounds were prepared using microwave-assisted reaction conditions, that provided higher yields in shorter times than the conventional methods.     

Reactions of N- and C-Alkenylanilines: III. Synthesis and Cyclization of Substituted 2-(1-Methyl-2-butenyl)anilines

Reactions of substituted 2-(1-methyl-2-butenyl)anilines with iodine result in cyclization and formation of 3-iodo-1,2,3,4-tetrahydroquinolines; N-methylsulfonyl-2-(1-methyl-2-butenyl)anilines give rise exclusively to the corresponding 2-(1-iodoethyl)-3-methyl-2,3-dihydroindoles.     

Unambiguously confirmed structure of 2-phenacylidene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one and 3-phenacylidene-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one

To determine the structures of two isomeric products, 2-phenacylidene-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one (2) and 3-phenacylidene-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one (3) obtained by condensation of 2,3-diaminopyridine (1) with ethyl benzoylpyruvate [1–3], these compounds were hydrolyzed to give 2-methyl-4H-pyrido[2,3-b]pyrazin-3-one (4) and 3-methyl-1H-pyrido[2,3-b]pyrazin-2-one (5) , respectively [4,5]. Both hydrolysates 4 and 5 were hydrogenated to afford 2-methyl-1,2-dihydro-4H-pyrido[2,3-b]pyrazin-3-one (6) and 3-methyl-3,4-dihydro-1H-pyrido[2,3-b]pyrazin-2-one (7) . The latter compound was identical with an unequivocally synthesized compound providing proof for the structures of all these compounds.     

2-Dichloromethyl-4-methyl-2,3-dihydrofuro[3,2-c]-quinoline derivatives

Substituted 2-dichloromethyl-4-methyl-2,3-dihydrofuro[3,2-c]quinolines were obtained by cyclization of substituted 2-methyl-3-(3,3-dichloroallyl)-4-hydroxquinolines, and 2-dichloromethyl-2,4-dimethyl-2,3-dihydrofuro[3,2-c]quinolines were isolated from 2-methyl-3-(2-methyl-3,3,dichloroallyl)-4-hydroxyquinolines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 84–86, January, 1973.     

Benzazoles: II. Synthesis and arenesulfonylation of 1-methyl-1H-benzimidazol-2-amine

The reaction of 1-methyl-1H-benzimidazol-2-amine with arenesulfonyl chlorides in the presence of triethylamine afforded 1-arenesulfonyl-3-methyl-2,3-dihydro-1H-benzimidazol-2-imines instead of expected N-(1-methyl-1H-benzimidazol 2-yl)arenesulfonamides.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give the corresponding 3-alkyl-5-acetyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Successive chlorination and dechlorination of 6-hydroxymethyl-1,4-dioxan-2-ones yielded 6-methylene-1,4-dioxan-2-ones.     

[3,3]-sigmatropic rearrangement of allyl 2-benzothienyl sulfide

Allyl 2-benzothienyl sulfide at 20–120 °C undergoes a [3,3]-sigmatropic rearrangement to give 3-allylbenzothiophene-2-thiol. The kinetic parameters of the reaction were studied. Under the experimental conditions the thiol undergoes cyclization to give 2-methyl-2,3-dihydrobenzothieno[2,3-b]thiophene, 2-methyl-benzothieno[2,3-b]thiophene, and benzothieno[2,3-b]dihydrothiopyran. Allyl 3-methyl-2-benzothienyl sulfide does not form a thiol even at 150–190 °C but rather forms only bis(3-methyl-2-benzothienyl) disulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 615–618, May, 1981.     

Synthesis of New Substituted 2,3-Dihydro-1,4-dioxin-2-ones and 1,4-Dioxan-2-ones

3-Alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones reacted with acetyl chloride in the presence of zinc(II) chloride to give 5-acetyl-3-alkyl-6-methyl-2,3-dihydro-1,4-dioxin-2-ones. Oxidation of the latter with hydrogen peroxide in formic acid, followed by treatment with magnesium bromide, afforded 3-alkyl-6-methyl-1,4-dioxane-2,5-diones. Chlorination of 6-hydroxymethyl-1,4-dioxan-2-ones with thionyl chloride and subsequent dehydrochlorination led to formation of 6-methylene-1,4-dioxan-2-ones.     

Some transformations of 2,3-diaminoindole derivatives. Synthesis of indolo[2,3-b]quinoxalines

1-Methyl-3-methoxy- and 1-methyl-3-piperidino-3-acetamidooxindole anils, respectively, were obtained by oxidation of 1-methyl-2-arylamino-3-acetamidoindoles with oxygen in the presence of copper acetate in methanol and in a mixture of dimethylformamide and piperidine. When the oxindole anils are heated, they undergo cyclization to indolo[2,3-b]quinoxalines. Indolo[2,3-b]quinoxaline N-oxides were obtained from the latter by the usual method.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1647, December, 1977.     

Benzofuran derivatives. Part 3 On the reactivities of the intermediates in benzofuran synthesis

3-Methyl-5-nitrobenzofuran ( 2 ) and 3-methyl-5-nitrobenzofuran-2-carboxylic acid ( 3 ) were obtained by heating 2-acetyl-4-nitrophenoxyacetic acid ( 1 ) with various bases in acetic anhydride. It appeared that 3-hydroxy-3-methyl-5-nitro-2,3-dihydrobenzofuran-2-carboxylic acid ( 4 ) was the intermediate in the benzofuran synthesis. The properties of 4 were examined under various conditions. Using strong bases such as triethyl-amine in place of sodium acetate, 3-methyl-5-nitrobenzofuran-2-carboxylic acid ( 3 ) was obtained exclusively. However, in the presence of acetic acid in the reaction mixture 3-methyl-5-nitrobenzofuran ( 2 ) was obtained in good yield. The reaction pathways for the formation of 2 and 3 are discussed.     

Condensed pyridazines. Part II. Synthesis of pyrido[2,3-C] pyridazines

The synthesis of some pyrido[2,3-c]pyridazines from 5,8-diehloro-3-methyl-2-oxo-2H-pyrano-[2,3-d]pyridazine (I) is described. Attempted oxidation of 8-amino-3-chloro-1,6-dimethyl-4,7-dioxo-1,4,7,8-tetrahydropyrido[2,3-c]pyridazine (VI) with LTA led only to the deaminated compound VII. Treatment of VI with LTA A in the presence of cyclohexene gave the nitrene adduct XI.