Study of the behavior of p-bis{3-[N,N-dialkyl-N-(4-hydroxybut-2-ynyl)ammonio]prop-2-ynyl}-benzene dichlorides in relation to aqueous alkali. Double intramolecular recyclization of benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichlorides

p-Bis{3-[N,N-dialkyl-N-(4-hydroxybut-2-ynyl)ammonio]prop-2-ynyl}benzene dichloride in the presence of catalytic amounts of aqueous alkali is subject to a double intramolecular cyclization forming benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichloride in 40–42% yield. Simultaneously an intramolecular recyclization takes place with the formation of dialkyl(6-dialkylaminomethyl-7,9,10,12-tetrahydro-8,11-dioxadicyclopenta[c,g]phenanthren-1-ylmethyl)amines in 7–9% yield. The same compounds are obtained in 70–72% yield by the recyclization of benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium dichlorides under conditions of aqueous alkaline degradation. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1329–1335, September, 2006.     

Preparative synthesis of veratraldehydeoxime esters

Preparative syntheses of veratraldehydeoxime esters 6–24, available fragrances produced from vanillin (1), in 82–92% yield from veratraldehydeoxime (3) were developed. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 558–560, November–December, 2008.     

Synthesis of 19-hydroxysteroids II. New synthesis of 19-hydroxyprogesterone

19-Hydroxyprogesterone has been synthesized in seven stages from pregnenolone with an overall yield of 11%. Institute of Bioorganic Chemistry, Belorussian Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 678–682, November–December, 1992.     

An Expeditious One-Pot Synthesis of N-Substituted 6-Nitroindoles from Indolines

Summary.  This paper reports an one-pot method for the concomitant alkylation – oxidation (aromatization) of indolines, particularly effective to get easy access to N-alkyl-6-nitroindoles, which are useful platforms in medicinal chemistry. N-alkyl-6-nitroindoles are obtained in good yield (64–91%) by reaction at room temperature in non-degassed DMF of 6-nitroindoline, an alkyl halide, and NaH as base. The presence of NaH appears to be essential for a high yield conversion. Corresponding author. E-mail: pdepreux@phare.univ-lille2.fr Received December 3, 2002; accepted December 9, 2002 Published online May 26, 2003     

Photoexcitation of the potassium octacyanotungstate(IV)· 5–nitro-1,10–phenanthroline system: kinetics and mechanism of the reaction

The kinetics of thermal reactions of the photochemically-generated species [W(CN)7OH]4− and [W(CN)6–(CNH)(H2O)]2− with 5–nitro-1,10–phenanthroline (nitrophen) in basic and acidic media, respectively, were studied in buffer solutions at pH 4.2–10.6 and ionic strength 7.5×10−2kg−1 at 20°C. The quantum yield for the formation of the photoproduct was calculated and found to depend upon pH and the ligand and [W(CN)8]4− concentrations. The rate constants and quantum yields were less compared with 1,10–phenanthroline due to the electron-withdrawing inductive effect of the nitro group in nitrophen, which makes the latter a weaker ligand. The pseudo-first-order rate constant and quantum yield values in acidic media are higher than in basic media and the mechanisms of the photochemical substitution are different in the two media. This revised version was published online in June 2006 with corrections to the Cover Date.     

Solvent-free regioselective synthesis of 6-and 7-substituted pteridines under microwave irradiation

Reactions of 5,6-diaminouracils with α-keto aldehydes over acidic and neutral aluminum oxide under microwave irradiation gave the corresponding 6-and 7-substituted 1,2,3,4-tetrahydropteridine-2,4-diones in 63–79% yield with high regioselectivity. Published in Russian in Zhurnal Organicheskoi Khimii, 2006, Vol. 42, No. 1, pp. 142–144. The text was submitted by the authors in English.     

Synthesis of Amido- and Diamidophosphites with Polyfluoroalkyl Substituents

Bis(polyfluoroalkyl) chlorophosphites and polyfluoroalkyl dichlorophosphites react easily with secondary amines (from –40 to –22°C, 1–3 h, CH2Cl2) in the presence or absence of triethylamine to form the corresponding bis(polyfluoroalkyl) diorganylamidophosphites or bis(diorganylamido) polyfluoroalkyl phosphites in the yield of up to 74%. Bis(polyfluoroalkyl) diorganylamidophosphites were also synthesized from diorganylamidodichlorophosphites and polyfluoroalkanols (–25 to –22°C, 2 h, Et3N–CH2Cl2) with a yield of 56–60%.     

Catalytic coupling of arenes with <Emphasis Type="Italic">p</Emphasis>-iodonitrobenzene in a system containing ArH,ArI, Pt<Superscript>II</Superscript>, 50% aqueous KOH,and 18-crown-6

The phenanthroline complex, Pt(phen)Cl₂, catalyzes the coupling of aromatic hydrocarbons with p-iodonitrobenzene under phase transfer conditions using 50% aqueous KOH and 18-crown-6. The yield of the asymmetric diaryl products is 10,000–12,000% relative to the catalyst. A mechanism was proposed involving the oxidative addition of ArI to an Ar-Pt^II intermediate species with subsequent reductive elimination of the final product Ar-Ar′ from Ar-Pt^IV-Ar′. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 6, pp. 364–366, November–December, 2007.     

Non-destructive profiling of fluorine in teeth to large depths

A new method for non-destructive depth profiling of fluorine has been developed which extends the profiling range to much larger depths than hitherto possible. In this method the thick-target yield of 6–7 MeV gammas from the reaction of ¹⁹F(p,αγ) ¹⁶O in the tooth sample, was measured as a function of the incident energy from threshold to up to 2.7 MeV and the yield curve plotted. This curve was compared to the calculated yield curve of 6–7 MeV gammas from the same reaction but on an enamel matrix containing uniformly distributed fluorine. The difference in the shape of the two curves was only due to the non-uniform distribution of fluorine in the tooth sample, which could then be calculated. By making use of this method F-depth profiles in teeth of monkeys were determined non-destructively to a depth of 14 μm. This method is also applicable for profiling other elements through appropriate resonant or non-resonant nuclear reactions.     

Composition and ethanol production potential of cotton gin residues

Cotton gin residue (CGR) collected from five cotton gins was fractionated and characterized for summative composition. The major fractions of the CGR varied widely between cotton gins and consisted of clean lint (5–12%), hulls (16–48%), seeds (6–24%), motes (16–24%), and leaves (14–30%). The summative composition varied within and between cotton gins and consisted of ash (7.9–14.6%), acid-insoluble material (18–26%), xylan (4–15%), and cellulose (20–38%). Overlimed steam-exploded cotton gin waste was readily fermented to ethanol by Escherichia coli KO11. Ethanol yields were feedstock and severity dependent and ranged from 58 to 92.5% of the theoretical yields. The highest ethanol yield was 191 L (50 gal)/t, and the lowest was 120 L (32 gal)/t.     

Microwave-Assisted Minutes Synthesis of Bioactive Phenylbutanoids Occurring in <Emphasis Type="Italic">Zingiber cassumunar</Emphasis>

Microwave-assisted condensation of benzaldehyde (3a,b) with acetone in aqueous sodium hydroxide adsorbed on basic alumina provides phenylbutenone (4a–4b) in 68–71% yield within 4 min, which upon further reduction with sodium borohydride and basic alumina gives phenylbutenol (5a,b) in 91–94% yield within 2 min. Dehydration of 5 with anhydrous copper (II) sulfate gives phenylbutadiene (1a,b), a metabolite of Zingiber cassumunar, within 3 min in 42–48% yield, respectively. All the steps involve environmental friendly solvents and reagents, mild reaction conditions, and overall formation of product 1a,b from 3a,b in 34–38% yield within 9 min under microwave irradiation. __________ Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 300–302, July–August, 2005.     

Polysaccharides from Fabaceae. IV. Galactomannan from <Emphasis Type="Italic">Gueldenstaedtia monophylla</Emphasis> seeds

Galactomannan (yield 1.73% of seed mass) with molecular weight 808 kDa was isolated from seeds of Gueldenstaedtia monophylla Fisch. (Fabaceae). Its solutions were typically highly viscous with [η] 664.7 mL/g and optically active with [α]_D +45.2°. It consisted of galactose and mannose in a 1:1.91 ratio. Physical chemical methods established that the principal chain of the polysaccharide consisted of 1,4-β-D-mannopyranose units substituted 50.1% in the C-6-position by single α-D-galactopyranose units and traces of 6-O-α-galactopyranosylgalactopyranose. The contents of mannobiose blocks substituted by galactose Man–Man, (Gal)Man–Man/Man–Man(Gal), and (Gal)Man–Man(Gal) in the galactomannan macromolecule were 23, 42, and 35%, respectively.     

Novel convenient synthesis of (Z/E)-8-dodecenyl acetates, components of the Grapholitha molesta sex pheromone

Components of the Grapholitha molesta sex pheromone, (Z/E)-8-dodecenyl acetates (1, 2), were synthesized in five steps in 20% overall yield using 10-hydroxydecanoic acid (3) as starting material. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 592–594, November–December, 2006.     

Gas phase nitration of benzene by nitric acid on ZSM-5 zeolite

Gas phase nitration of benzene on ZSM-5 zeolite has been studied at 140–170°C. Increase in the HNO₃/C₆H₆ ratio of the starting mixture was shown to increase the nitrobenzene yield. Process parameters worsened with time since reagents and products were strongly adsorbed and left the zeolite surface only at 220–250°C as CO, CO₂ and NO.     

Synthesis of Non-Symmetric Functionalized Polyfluoroalkyl Phosphites

Two ways for the synthesis of new representatives of non-symmetric organic phosphites with polyfluoroalkyl substituents were developed based on organic dichlorophosphites. The reaction of polyfluoroalkyl dichlorophosphites with allyl alcohol, proceeding at a temperature of –10–22°C (2 h) in the presence of triethylamine, gave diallyl polyfluoroalkyl phosphites in a yield of 75–77%. Under similar conditions (–30–22°C, 2–4 h, Et3N), alkyl (or aryl) dichlorophosphites reacted with polyfluoroalkanols to form alkyl (or aryl) bis(polyfluoroalkyl) phosphites (yield 56–67%). Unlike diallylpolyfluoroalkyl- and alkylbis(polyfluoroalkyl) phosphites, arylbis(polyfluoroalkyl) phosphites are symmetrized under storage conditions (room temperature, inert atmosphere), forming the corresponding triaryl- and tris(polyfluoroalkyl) phosphites.     

Synthesis and biodistribution of a novel <Superscript>99m</Superscript>Tc complex of HYNIC-conjugated metronidazole as a potential tumor hypoxia imaging agent

A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with the amino analogue of metronidazole (MN) was synthesized through a multiple-step reaction. HYNIC-MN could be labeled easily and efficiently with ^99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) and ethylenediamine -N,N′-diacetic acid (EDDA) as coligands to form the ^99mTc–HYNIC–MN complex in high yield (>95%). Its partition coefficient indicated that it was a good hydrophilic complex. The tumor cell experiment showed that the ^99mTc–HYNIC–MN complex had a certain hypoxic selectivity. The biodistribution studies of ^99mTc–HYNIC–MN in Kunming mice bearing S180 tumor showed a favorable tissue distribution profile with high tumor uptake, and low or negligible accumulation in non-target organs, suggesting ^99mTc–HYNIC–MN would be a novel potential tumor hypoxia imaging agent.     

Effect of alkali metal additives on the activity and selectivity of structured silver catalysts in epoxidation of ethylene by nitrogen(I) oxide

We have shown that introducing Cs, K, or Na additives into the composition of silver catalysts (supported on ceramic honeycomb monoliths) for epoxidation of ethylene by nitrogen(I) oxide leads to an increase in the yield of the target product (ethylene oxide) by a factor of 1.5–2, while the presence of lithium in the composition of the composites inhibits the process. The optimal content of alkali promoters in the composition of the catalysts decreases in the series Na, K, Cs antibatically relative to the ionic radii of the elements. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 41, No. 6, pp. 360–363, November–December, 2005.     

Synthesis of <Emphasis Type="Italic">α</Emphasis>-chloropyridine derivatives of <Emphasis Type="Italic">γ</Emphasis>-aminobutyric acid

The sodium salt of N-(6-chloronicotinoyl)-γ-aminobutyric acid, a structural analog of the known nootropic and vasidilating drug picamilon, was synthesized via Schotten–Baumann acylation of γ-aminobutyric acid with 6-chloronicotinoyl chloride and subsequent neutralization of the N-(6-chloronicotinoyl)-γ-aminobutyric acid that was obtained in >60% yield.     

Synthesis and biological evaluation of a novel <Superscript>99m</Superscript>Tc complex of HYNIC-conjugated aminomethylenediphosphonate as a potential bone imaging agent

A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with ^99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the ^99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The biodistribution studies of ^99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target organs. As compared with ^99mTc–MDP, ^99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations of the biological behavior of this complex.     

Synthesis of 6α-methyl-16α, 17α-cyclohexanoprogesteronevia γ-methylenation of 16α, 17α-cyclohexanopregn-4-ene-3,20-dione

6-Methylene-16α, 17α-cyclohexanopregn-4-ene-3,20-dione 2 has been synthesized by the reaction of Δ⁴-3-ketone1 with CH₂(OEt)₂ and POCl₃ in the presence of AcONa in 55% yield. Reduction of the product2 in the presence of 5% Pd/C gives 6α-methyl-16α, 17α-cyclohexanoprogesterone3 in a yield exceeding 70%. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1234–1236,June, 1997.