Synthesis of naphthalene and indene precursors to naphthoic and indenoic acids

As part of ongoing research to investigate structural requirements for lactate dehydrogenase inhibition by highly substituted naphthoic and indenoic acids, certain naphthalene and indene precursors to those types of compounds are required. Described here are efficient preparations of 1-naphthoic acid precursors 6-benzyl-2,3-dimethoxy-1-propylnaphthalenes, including compounds with substituted benzyl groups and 7-benzyl-2,3-dimethoxy-1-propylnaphthalene. Also described are the syntheses of indenoic acid precursors 2-benzyl-5,6-dimethoxy-7-propyl-1H-indenes, including compounds with substituted benzyl groups. These compounds were made from the key intermediates 6,7-dimethoxy-5-propyl-1-tetralone, 6,7-dimethoxy-8-propyl-1-tetralone, and 5,6-dimethoxy-4-propyl-1-indanone.     

Identification and simultaneous determination of non-steroidal anti-inflammatory drugs using high-performance liquid chromatography

An isocratic high-performance liquid chromatographic procedure is presented for the screening of plasma samples for the presence of sixteen non-steroidal anti-inflammatory drugs. Detection was achieved simultaneously at two wavelengths (254 and 370 nm) and the purity of the eluted peaks was tested using absorbance ratios at the two wavelengths; identification could thus be effective without interferences from substances of other pharmacological classes. The drugs were extracted simultaneously with diethyl ether after acidification and separated from each other on an octadecyl reversed-phase column using only one eluent, acetonitrile-0.3% acetic acid-tetrahydrofuran (36:63.1:0.9, v/v). The recovery, precision and reproducibility of the method were satisfactory as it allowed the determination of the drugs from infra- to supratherapeutic concentrations.     

Sur une transformation inhabituelle de nitro-2 benzofurannes dans les conditions de la reaction de friedel et crafts

On treatment with acetyl chloride or acetic anhydride in presence of aluminium chloride in methylene chloride. 2-nitro and 5-chloro 2-nitro benzofurans yield 2,3-dichloro benzofurans, 3-chloro 2-coumaranones and 2-acetoximino 3-chloro coumarans. By the action of acetyl chloride, in presence of titanium (IV) chloride in methylene chloride, on 2-nitro benzofuran, 2,3-dichloro benzofuran can be obtained with a fairly good yield beside a relatively restricted quantity of 3-chloro 2-coumaranone. In the same conditions, 5-chloro-2-nitro benzofuran yields not only 2,3,5-trichloro benzofuran but also 2,2,3,3,5-pentachloro coumaran and, occasionally. 3,5-dichloro 2-coumaranone.     

Calcul pseudodifférentiel en grande dimension et limites thermodynamiques

If P_n(h) is a h-pseudodifferential operator in $\text{R}{}^{\mathrm{n}}$ associated to an holomorphic semi-bounded symbol in some neighborhood of the real phase space, with bounded derivatives, we describe the symbol of e^?tP_n(h), by inegalities where the constants depend on the bounds for the derivatives of the symbol of P_n(h), but not on the dimension n. Some applications to thermodynamic limits are given. To cite this article: C. Royer, C. R. Acad. Sci. Paris, Ser. I 336 (2003).     

Action des composes organomagnesiens sur les pyrones-2—IX : Etude des différentes voies réactionnelles

The formation of the dihydropyranol 15 during the synthesis of the 6-hydroxy-4-heptene-2-one (Z) 14 indicates the possibility of an equilibrium between ketols (Z) 5 and pyranols 6. This equilibrium lies well to the side of the pyranol. It might be argued that the dihydropyranol compounds prepared from 2-pyrones and Grignard reagents can be derived from the Z ethylenic ketols.Criteria for the reaction scheme are provided by the stereoselectivity of intermediates in agreement with MNDO (modified neglect of diatomic overlap) calculations.A brief discussion of the present knowledge on the different reaction schemes concerning the reaction of Grignard reagents with 2-pyrones is added.     

Immobilization of growing cells by polyethyleneimine-modified alginate

A unique polymer matrix that is suitable for immobilizing growing cells has been developed. Alginate was chemically modified with polyethyleneimine (PEI), and the resultant polymer aggregate was evaluated as a cell carrier. Our method of immobilization depends on reversible gelation of the PEI-modified alginate. Our hypothesis is that immobilized cells grow by dissolving the surrounding gel matrix; the dissolved polymer adduct is displaced peripherally and gelled again by the influx of calcium ion from the surrounding fermentation broth, retaining both cells and carrier polymer in the gel beads. Thus, the immobilized cells gain space for growth by expanding the carrier matrix. The PEI modification offers the following advantages: (1) improved mechanical strength; (2) improved cell retention; (3) increased catalyst life; (4) ease of pelletization; and (5) an apparent bacteriostatic capability. When immobilized yeast cells were applied to a continuous ethanol fermentation, 94% theoretical conversion of glucose to ethanol was observed, with a reactor productivity of 15–30 g/L/h in a nonsterile reactor. A 3-mo catalyst life and minimal cell washout were observed.     

Sur une transformation inattendue du β-methyl β-nitrostyrene en aldehyde salicylique

An unexpected route to o-hydroxybenzaldehyde is described. Thus, β-methyl β-nitrostyrene mixed with acetyl chloride and aluminium chloride at 0° yields upto 45% salicylaldehyde besides 2-acetoximino 1-chloro 1-phenyl propane and dichloromethyl benzene as minor products.     

Recherches sur le benzofuranne,LVII. Sur une chloration inhabituelle de l'hétérocycle au cours de la réduction des (nitro-4 phényl)-2 ou -3 benzo-furannes par le chlorure stanneux

Reductions of 2-(4-nitrophenyl)- and 3-(4-nitrophenyl)benzo-furans by stannous chloride in presence of hydrochloric acid yield not only the expected 2-(4-aminophenyl)- and 3-(4-amino-phenyl)-2-chlorobenzofurans but also the 2-(4-aminophenyl)-3-chloro- and 3-(4-aminophenyl)-2-chlorobenzofurans the structures of which have been ascertained by their ¹³C nmr spectra, by comparison with those of 2-phenyl- and 3-phenylbenzofurans. These interfering chlorinations are most likely due to a radical mechanism.     

Asymmetric synthesis V. Enantiospecific synthesis of β-aminoalcohols in the piperidine series : (+)-β-conhydrine

The first enantiospecific synthesis of the piperidine derivative (+)-β-conhydrine $\text{4}$ has been achieved from the chiral 2-cyano-6-oxazolopiperidine synthon $\text{1}$.     

Interaction between neighboring aromatic and polar group—II : Study of n-substituted 3-(3'-indolyl) norbornene 2-carboxylic acids

The synthesis of a series of title compounds and of 3-isopropyl norbornene 2-carboxylic acids is described. Different pK_a values have been found for the isomeric acids trans1 and cis2, having the same indolic substituent. This fact can be attributed to a through space interaction between the neighboring aromatic and carboxylic groups.