Fluorénacènes et fluorénaphènes synthèses dans la série des indéno-fluorènes,XVII. Dérivés méthylés du cis-fluorénacène,du trans-fluorénacène et du trans-fluorénaphène

By condensation of the chlorides of the three 9-oxo-fluorene-2-, -3-, and -4-carboxylic acids with 4-bromo-1,2-xylene on one side, and of the chlorides of o-bromobenzoic acid, 2-bromo-4-methyl-benzoic acid and 2-bromo-4,5-dimethyl-benzoic acid with fluorene, 2-methylfluorene and 3-methylfluorene on the other side, followed by direct or indirect cyclisation and by final reduction, several new methyl derivatives of the indenofluorenes I, II and IV are synthesized.     

Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno-fluorènes,XVIII. Le diméthyl-5, 6-dihydro-7, 12-indéno[1, 2-a]fluorène

Starting from 3, 4-dimethylfluorene the title compound, 5, 6-dimethyl-7, 12-dihydro-indeno[1,2-a]fluorene (IV), is synthesized in four steps (overall yield 9%). The same hydrocarbon is also obtained in four steps starting from the phthalaconecarboxylic acid of Gabriel. This corroborates the structure of IV.     

The structure–activity relationship of some hexacoordinated dimethyltin(IV) complexes of fluorinated β‐diketone/β‐diketones and sterically congested heterocyclic β‐diketones

The study was focused on the structure–activity relationship of some newly synthesized hexacoordinated dimethyltin(IV) complexes of fluorinated β‐diketone/β‐diketones and sterically congested heterocyclic β‐diketones. These complexes were screened for their antibacterial activity against a Gram‐negative bacterium (Pseudomonas aeruginosa) and Gram‐positive bacteria (Streptomyces griseus, Staphylococcus aureus, Bacillus subtilis) and the results were compared with those of a standard antibacterial drug. Some of the complexes were also screened for their antifungal activity against various fungi (Aspergillus niger, A. flavus, Trichoderma viride, Fusarium oxysporum) and were found to be active. These new hexacoordinated complexes of dimethyltin(IV) were generated by reactions of dimethyltin(IV) dichloride and sodium salts of fluorinated β‐diketone/β‐diketones and sterically congested heterocyclic β‐diketones in 1:1:1 molar ratio in refluxing dry benzene. Plausible structures of these complexes were suggested with the aid of physicochemical and spectroscopic studies. ¹¹⁹Sn NMR spectral data revealed the presence of a hexacoordinated tin centre in these dimethyltin(IV) complexes. Copyright © 2015 John Wiley & Sons, Ltd.     

Etudes photochimiques en série hétérocyclique. V. Mise en évidence d'oxazoles par photooxydation de thiazoles

Formation of oxazoles as by-products of photooxydation of thiazoles In the presence of air, light (high pressure mercury lamp) and iodine as sensitizer, benzene solution of arylthiazoles 2 , 3 and 13 (see scheme 1) were converted into a mixture of photoisomers and aryloxazoles (see scheme 2). Upon shorter times of irradiation under oxygen in chloroform containing methylene blue as a sensitizer 2,4,5-triphenylthiazole (7) is converted in 2,4,5-triphenyloxazole. Under usual photooxidation conditions, in methanol as solvent, most of arylthiazoles studied gave a mixture of nitriles, amides, acids esters and diketones. In the case of thiazole 7 , the corresponding oxazole was also found. A possible mechanism for the photochemical oxidation of arylthiazoles to aryloxazoles, via 2,5- and 4,5-endo-peroxides, may be proposed (see schemes 5 and 6).     

Réactions de Friedel et Crafts de dérivés aromatiques sur les composés dioxo-1,4,2,3-non saturés. IV. Réactions des hydroxy-5-ouchloro-5-diméthyl-3,5- ou diméthyl-4,5-dihydro-2,5-furannones-2

Friedel-Crafts reactions of aromatic derivatives with 1,4-dicarbonyls 2,3-éthylenic compounds. Part IV. Reactions of 5-hydroxy or 5-chloro 3,5-dimethyl or 4,5-dimethyl 2 (5 H) furanones We studied the Friedel-Crafts reactions of 2-(5H)-furanones. In the presence of sulfuric acid and of an aromatic derivative, 5-hydroxy- or 5-chloro-5-methyl-2-(5H)-furanones with one methyl group either in the 3 position, or in the 4 position generally give the corresponding 5-aryl-2-(5H)-furanones, while with aluminium chloride, it is possible to obtain, when a reaction takes place, isomeric 1H-indenecarboxylic acids. However, in a particular case, an addition to the substrate's double bond is observed. The 3-aryl-5-hydroxy-tetrahydrofuran-2-one obtained is methylated in two ways and gives either a cyclic product, or a linear one. In two cases tautomerism between 1H-1-indenecarboxylic acid and 1H-3-indenecarboxylic has been shown by ¹H-NMR.     

Indole derivatives

A method for the introduction of a 3-indolyl group in compounds with an active methylene group was developed. The corresponding 3-indolyl diketones were obtained by condensation of 1-acetyl-3-indolinone with dimedone, 4-hydroxycoumarin, 1,2-diphenyl-3,5-pyrazolinedione, and barbituric and thiobarbituric acids and subsequent alkaline hydrolysis of the condensation products. The existence of cyclic six-membered 3-indolyl diketones in the enol form and of cyclic five-membered 3-indoly diketones in the keto form was shown by IR and UV spectroscopy. Depending on the conditions, (1-acetyl-3-indolyl)cyanoacetamide, 1,3-bis(1-acetyl-3-indolyl)-1,3,3-tricyano-2-amino-1-propene, and 1-acetyl-3-indolylmalononitrile are obtained in the condensation of 1-acetyl-3-indolinone with malononitrile. 1-Acetyl-3-indolylmalononitrile exists in equilibrium with the keteneimine form and in protic solvents is converted to 3-cyano-8-acetylpyrrolo[2,3-b]indole by intramolecular cyclization.See [1] for communication CX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–368, March, 1977.     

Uncatalyzed reaction of silyl ketene acetals with oxalyl chloride: a straightforward preparation of symmetrical pulvinic acids

[reaction: see text] Several natural pulvinic acids were synthesized. Silyl ketene acetals derived from methyl arylacetates (4 equiv) reacted with oxalyl chloride at -78 degrees C, without the need of adding a catalyst. After treatment of the crude diketones with DBU and acidification with hydrochloric acid, symmetrical pulvinic acids methyl esters were obtained. Saponification of the methyl esters afforded the corresponding pulvinic acids in 60-70% overall yields from oxalyl chloride.     

Addition of carboxylic acids and cyclic 1,3-diketones to 2-dimethylamino-3,3-dimethyl-1-azirine

The reaction of 2 - dimethylamino - 3,3 - dimethyl - 1 - azirine 1 with carboxylic acids 2a-e at room temperature in inert solvents generates rearranged 1:1 adducts in 65–92% yields. These adducts are N-acyl derivatives of 2-amino, -N,N dimethyl-isobutyramide 3a-e resulting from 1,2 addition of the acid followed by 1,2 ring cleavage and transfer of an acyl group. Cyclic enolizable 1,3 diketones 4a-c react similarly with 1 to yield the corresponding rearranged 1:1 adducts 5a-c, whereas acyclic diketones or ethyl acetoacetate are inert under comparable experimental conditions.     

Synthesis of annularly functionalized cyclophanes

Friedel-Crafts reaction of m- and p-benzenedicarboxylic acid chlorides with toluene gave diketones. The dicarbonyl dibromides, obtained by NBS bromination of diketones were coupled with various dithiols and dihydroxy benzenes to give cyclophanes incorporating two carbonyl groups. The dicarbonyl dibromide, derived from isophthalic acid chloride was converted into dithiol, which on coupling with the same dibromide afforded cyclophane incorporating four carbonyl groups. The NaBH₄ reduction of the tetraketone cyclophane in methanol gave the tetraalcohol derivative.     

Anodic reductions—V The reduction of diketones by unipositive magnesium anodically generated

A series of diketones of the general formula C₆H₅CO(CH₂nCOC₆H₅ has been prepared and subjected to “anodic reduction” in sodium iodide-pyridine solution between magnesium electrodes. In every case hydrolysis of the anolyte following electrolysis yielded a 1:2-diol as the reduction product as evidenced by titration with standard lead tetraacetate solution. The diketones, 1:3-dibenzoylpropane (n = 3) and 1:4-dibenzoylbutane (n = 4), gave cis-1:2-diphenylcyclopentane-1:2-diol and cis-1:2-diphenylcyclohexane-1:2-diol, respectively. On the assumption that the other diketones also gave cyclic 1:2-diols, there is a striking correlation between the initial mean valence number (V_i) of the magnesium entering solution from the anode and the size of the ring; the lowest V_i values were obtained in those instances where the diketones originally in solution gave the most stable cyclic diols. Interpretations are offered for these results and for corrosion phenomena observed.     

Synthesis of 8,9‐dialkoxybenzodiazepines and 7,8‐dialkoxyisoquinolines

o‐Aroylarylacetone type 1,5‐diketone derivatives (5, 6) were synthesised from arylacetones (1) protected as 1,3‐dioxolanes (4) through directed ortho lithiation followed by acylation with aroyl chlorides. 8,9‐Dialkoxy‐2,3‐benzodiazepines 9 were obtained by cyclisation of diketones 6 with hydrazine. The reaction of diketones 6 with ammonia gave 7,8‐dialkoxyisoquinolines 11. Reaction of ketals 5 with hydrazine hydrochloride and hydroxylamine hydrochloride afforded N‐amino‐7,8‐dialkoxyisoquinolinium chlorides (10) and 7,8‐dialkoxyisoquinolinium oxides (12), respectively.     

Investigation of pharmacophore and antipharmacophore features of certain dimethyltin(IV) complexes of flexible N‐protected amino acids and fluorinated β‐diketone/β‐diketones

A set of pentacoordinated dimethyltin(IV) complexes of flexible N‐protected amino acids and fluorinated β‐diketone/β‐diketones was screened for their antibacterial activity against Pseudomonas aeruginosa , Staphylococcus aureus and Streptomyces griseus . These pentacoordinated complexes of the type Me₂SnAB (where : R = CH(CH₃)C₂H₅, A₁H; CH₂CH(CH₃)₂, A₂H; CH(CH₃)₂, A₃H; CH₂C₆H₅, A₄H; and BH = R'C(O)CH₂C(O)R″: R′ = C₆H₅, R″ = CF₃, B₁H; R′ = R″ = CH₃, B₂H; R′ = C₆H₅, R″ = CH₃, B₃H; R′ = R″ = C₆H₅, B₄H) were generated by the reactions of dimethyltin(IV) dichloride with sodium salts of flexible N‐protected amino acids (ANa) and fluorinated β‐diketone/β‐diketones (BNa) in 1:1:1 molar ratio in refluxing dry benzene solution. Plausible structures of these complexes were elucidated on the basis of physicochemical and spectral studies. ¹¹⁹Sn NMR spectral data revealed the presence of pentacoordinated tin centres in these dimethyltin(IV) complexes.     

N-heterocyclic carbene catalysed homoenolate addition to 3-methyl-4-nitro-5-styrylisoxazoles

We describe the development of an N-heterocyclic carbene catalysed homoenolate addition to 4-nitro-5-styrylisoxazoles to give substituted cyclopentanones with a unique substitution pattern and as single diastereoisomers. The synthetic utility of the cyclopentanones obtained was briefly explored through their conversion into α-fluorinated diketones and keto acids.     

Effect of fluorinated/non‐fluorinated β‐diketones and side‐chain branching of N‐protected amino acids on the antibacterial potential of new heptacoordinated monobutyltin(IV) complexes

The effect of fluorinated/non‐fluorinated β‐diketones and side‐chain branching of N‐protected amino acids on the antibacterial potential of new heptacoordinated monobutyltin(IV) complexes was investigated. New heptacoordinated monobutyltin(IV) complexes having the general formulae BuSn(A)₂B and BuSnA(B)₂ [where AH = (1,3‐dihydro‐1,3‐dioxo‐α‐(substituted)‐2H ‐isoindole‐2‐acetic acids, N‐protected amino acids), R =  CH(CH₃)CH₂CH₃: A₁H; R =  CH(CH₃)₂: A₂H; and BH = R'COCH₂COR″ (β‐diketones), R′ = R″ =  CH₃: B₁H; R′ =  CH₃, R″ =  C₆H₅: B₂H; R′ =  CF₃, R″ =  C₆H₅: B₃H] were synthesized. Complexes BuSn(A)₂B and BuSnA(B)₂ were generated by the reaction of sodium salts of the ligands AH and BH with BuSnCl₃ in 2:1:1 and 1:2:1 molar ratios, respectively. These newly generated complexes were characterized in physicochemical and spectroscopic studies. These complexes contain heptacoordinated tin centres as revealed by ¹¹⁹Sn NMR chemical shift values. Some of the newly generated complexes and their corresponding ligands were screened for their antibacterial activity to study the structure–activity relationship.     

Hydrolyse acide des diazocétones secondaires: Participation des nucléophiles

In the acid hydrolysis of two secondary diazoketones showing rate-determining protonation, 3-diazo-butan-2-one ( 1 ) and 1-phenyl-1-diazo-acetone ( 4 ), the nature of the (rapid) decomposition step of the intermediate diazonium ion was studied by product analysis. In the presence of strong nucleophiles, the reaction with Cl^?, Br^?, I^? and SCN^? follows the Swain-Scott relationship. SCN^? formed thiocyanates; isothiocyanates could not be detected. Both results indicate nucleophilic participation in the substitution step. For the accompanying elimination reaction (the amount of which is independent of added base) the isotope effect k_H/k_D = 2,4 in the hydrolysis of 1–d₃ is in favour of an E2 type mechanism. – Addition of HSCN to methyl-vinylketone at 0° yields nearly exclusively 4-thiocyanato-butan-2-one, which at 25° in the presence of HSCN is slowly rearranged to 4-isothiocyanato-butan-2-one.     

Catalyse acide de certaines réactions nucléophiliques en série phosphoranique. - Action de l'anhydride chloracétique sur les alcoxycarbonylméthylène-phosphoranes

(Alkoxycarbonyl-chloroacetyl-methylene)-phosphoranes dealkylate in the presence of acids and give the very stable lactone-betaine IV. The mechanism of this reaction is tentatively compared to other known dealkylations catalysed by protons or quaternary phosphonium compounds.     

Some fatty acids having an O-heterocycle in their terminal positions. II. ω-(3-Coumarinyl)alkanoic acids and ω-(2-chromonyl)alkanoic acids

Some ω-3-coumarinyl)alkanoic acids 1a , n = 3-6 were synthesized by cyclization of corresponding ethyl o-formylphenyl alkanedioate 3 with DBU followed by hydrolysis. By a similar cyclization, some ω-(2-chromonyl)alkanoic acids 2a , n = 3-6 were also obtained from the cyclization of corresponding o-acetylphenyl ethyl alkanedioate 4 .     

Kinetics of Ce(IV) oxidation of α-keto acids in sulfuric-perchloric acid media

The rates of oxidation of four α-keto acids, glyoxylic, pyruvic, phenylglyoxylic, and 2-oxobutyric acids by Cerium(IV) in H₂SO₄? HaHSO₄ and H₂SO₄? HClO₄ solutions, have been studied spectrophotometrically. The rate data suggest that CeSO is the most reactive of the Cerium(IV)-sulfate complexes present in the H₂SO₄? NaHSO₄ and H₂SO₄? HClO₄ systems. The oxidation reaction is proposed to be a one-electron process with the rate-determining step being the decomposition of a α-ketoacid-Cerium(IV) complex to a free radical and carbon dioxide through a transition state.     

Synthèses dans la série des bis-indéno-anthracènes,I Le tétraoxo-5, 10, 15, 16-tétrahydro-5, 10, 15, 16-bis-indéno [2.1-a; 2′.1′-c] anthracène et le dihydro-5, 16-bis-indéno [2.1-a; 2′.1′-c] anthracène

Starting from 5-carboxy-6-methyl-7, 12-dioxo-7, 12-dihydro-indeno [1.2-a] fluorene (phthalacone-carboxylic acid) the first title compound, XI, has been synthesized in 4 steps (overall yield 28%). By anindependent way the corresponding hydrocarbon (second title compound, IV) has been obtained in 3 steps (overall yield 35%) starting from 2, 3′-bi-indenyle and 1, 4-naphthoquinone.     

Mittlere ringe-XIII Die intramolekulare acylierung der ω-(1-naphthyl)-fettsäuren

The intramolecular Friedel-Crafts cyclisation of ω-arylalkanoic acids, which is in the benzene series a valuable synthetic route to bicyclic ketones with medium-sized and large rings, has been investigated with ω-(1-naphthyl)alkanoyl chlorides. The lower members, including naphthyl-caproic acid, close the ring at position 2 to form IV. The higher homologous acids show a preference for annellation at 7, making available a new type of heteronuclear naphthalene cyclic ketones (VII). During cyclisation of ω-(1-naphthyl) decanoic acid, the 1,4 ring closure competes with the 1,7 type.

Steric hindrance of resonance as a consequence of “medium ring torsion” was studied in different classes of naphthocyclenones.