Spectrofluorimetric determination of 1-(3-chlorophenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine

A sensitive fluorimetric method for the determination of 1-(3-chlorophenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine (5 × 10^?8?6 × 10^?4) g ml^?1) is described. The method is based on acid hydrolysis and aldol condensation in alkaline solution to give a compound which shows intense fluorescence at 440 nm.     

Spectrofluorimetric method for the determination of 1-(3,4-dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benzodiazepine (tofisopam)

The method described is based on the reaction of tofisopam in dimethyl sulphoxide in the presence of an alkali metal hydroxide at 90–100°C to give 1-ethyl-4-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2-naphthol, which shows intensive fluorescence. The method is suitable for the determination of 5 × 10^?8?5 × 10^?5 g ml^?1 of tofisopam.     

Immobilized-enzyme electrode for nicotinamide adenine dinucleotide (reduced form) (NADH) sensing and application to the kinetic studies of NADH dependent dehydrogenases.

Amperometric determination of nicotinamide adenine dinucleotide (reduced form) (NADH) at an immobilized-diaphorase (Dp) electrode is described. The measurement was conducted using ferrocenylmethanol as a mediator in a stirred solution at 0.20 V versus a saturated calomel electrode. A linear relationship between the steady-state current and the concentration of NADH was found over the range 0.005-0.125 mmol dm-3. The immobilized-Dp electrode showed outstanding stability and the current response reached a steady state within 2-3 seconds upon addition of NADH. The proposed electrode was used to follow the reactions of pig heart lactate dehydrogenase and horse liver alcohol dehydrogenase. The kinetic investigation using the immobilized-Dp electrode gave the kinetic parameters (Michaelis constants, Km values, and maximum velocities, Vm values), which were in satisfactory agreement with those determined by a conventional spectrophotometric method.     

Synthesis and antitumor activity of 6- and 2- （ 1-acyl sulfanylalkyl）-5,8-dimethoxy- 1,4-naphthoquinones

Sixteen novel 6- and 2-（1-acylsulfanylalkyl）-5,8-dimethoxy-l,4-naphthoquinones were designed and synthesized. Their cytotoxicities were evaluated in vitro against BEL-7402, HT-29 and SPC-Al cell lines. The pharmacological results showed that most of the prepared compounds displayed the excellent selectivity for HT-29 cell line. Compound lab exhibited the most potent antitumor activity among the tested compounds.     

Unexpected formation of 6-methyl-4-(5-methylfuran-2-yl)-2-ethylsulfanylpyridine-3-carbonitrile from 2-methyl-4-(5-methylfuran-2-yl)-N-o-tolyl-5-cyano-6-ethylsulfanyl-1,4-dihydropyridine-3-carboxamide

Russian Journal of Organic Chemistry -     

Asymmetric synthesis of (R)-(+)-6-(1,4-dimethoxy-3-methyl-2-naphthyl)-6-(4-hydroxyphenyl)hexanoic acid as a key intermediate for a neurodegenerative disease agent

An asymmetric synthesis of (R)-(+)-6-(1,4-dimethoxy-3-methyl-2-naphthyl)-6-(4-hydroxyphenyl)hexanoic acid 2 as a key intermediate for a neurodegenerative disease agent 1 has been developed. A key reaction was an asymmetric hydrogenation of hindered acrylic acid 13 catalyzed by the Rh-JOSIPHOS system in the presence of a base to afford a chiral acid up to 93% ee.     

Reaction of 5-(3,4-dimethoxyphenyl)pyrazine-2,3-dicarbonitrile with alkyl radicals

The reaction of 5-(3,4-dimethoxyphenyl)pyrazine-2,3-dicarbonitrile (Ib) with alkyl radicals gives addition products at the C(6)-position of the pyrazine ring as the intermediates which collapse into substitution products, 6-alkyl-5-(3,4-dimethoxyphenylpyrazine-2,3-dicarbonitrile (II), under oxidative conditions. Under non-oxidative conditions the intermediate is converted into dihydropyrazine derivatives, 6-alkyl-(3,4-dimethoxy-phenyl)-5,6-dihydropyrazine-2,3-dicarbonitrile (III), and 3,6-disubstituted pyrazine derivatives, 3,6-dialkyl-5-(3,4-dimethoxyphenyl)pyrazine-2-carbonitrile (IV) and 3-acyl-6-alkyl-5-(3,4-dimethoxyphenyl)pyrazine-2-carbonitrile (V).     

Synthesis and some conversions of 4-aryl-6-methyl-2-methoxy(phenyl)-5-nitro-1,4-dihydropyrimidines

The reaction of 1-arylidene-1-nitropropan-2-ones with O-methylisourea (or benzamidine) in the presence of aluminum oxide gave 4-aryl-6-methyl-2-methoxy(phenyl)-5-nitro-1,4-dihydropyrimidines. It was shown that the reactions of the compounds synthesized with electrophilic agents proceed at the exocyclic methyl group, as well as at the N₍₁₎, N₍₃₎, and C₍₅₎ atoms of the 1,4-dihydropyrimidine fragment of the molecule.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1398–1404, October, 1993.     

Racematspaltung von (±)-5-äthyl-1-(3,4-dimethoxyphenyl)-6,7-dimethoxy-4-methyl-5H-2,3-benzodiazepin und anomales chiroptisches verhalten der enantiomeren

A process has been developed for resolving 1 , and the anomalous behaviour of the specific rotation of the enantiomers has been studied. It was shown that this is due to the shift in the conformational equilibrium la ? Ib , and not to an epimerization at C-5.     

Studies on the interaction of Eu(III) with lawsone (2-hydroxy-1,4-naphthoquinone), lapachol (2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone), juglone (5-hydroxy-1,4-naphthoquinone) and plumbagin (2-methyl-5-hydroxy-1,4-naphthoquinone)

pH-metric studies show that one mole of Eu(III) interacts with three molecules of each of juglone, plumbagin, lawsone and lapachol in solution. The stability and thermodynamics of these systems (50% aqueous acetone, 0.1 M KNO₃ ionic strength) are discussed and explained.     

Synthesis and properties of N-methylmorpholinium 6-methyl-4-(4-pyridyl)-5-phenylcarbamoyl-3-cyano-1,4-dihydropyridine-2-thiolate

Condensation of acetoacetic acid anilide, 4-pyridyl aldehyde, cyanothioacetamide and N-methylmorpholine gave N-methylmorpholinium 6-methyl-4-(4-pyridyl)-5-phenylcarbamoyl-3-cyano-1,4-dihydropyridine-2-thiolate from which were obtained the corresponding substituted pyridinethiones, 2-alkylthio-1,4-dihydropyridines and 3-amino-2-benzoyl-6-methyl-4-(4-pyridyl)-5-phenylcarbamoylthieno[2,3-b]pyridine.T. G. Shevchenko Lugansk Pedagogical Institute, Lugansk 348011. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 672–675, May, 1997.