Tetrahydrofuran naphthalene

Reaction with tetrahydrofurane. Naphthalene-lithium (I) reacts with tetrahydro-furane at 65 to give the alcohols (2) and (3). ... 

Bromonaphthalene refluxed 3 hrs. with LiAlH4 and TiCl4 in tetrahydrofuran naphthalene. Y 98%. - The Lewis acid TiCl4 has a strong affinity toward halogen. F. e. and reductions s. T. Mukaiyama, M. Hayashi, and K. Narasaka, Chem. Lett. 1973, 291. 

In the presence of certain ethers such as Me20, Me0CH2CH20Me or tetrahydrofuran, Na forms deep-green highly reactive paramagnetic adducts with polynuclear aromatic hydrocarbons such as naphthalene, phenanthrene, anthracene, etc. ... 

To a solution of 0.6 g naphthalene in 10 ml tetrahydrofurane, anhydrous, used as solvent, add 96 mg sodium under a nittrogen atmosphere. After a few minutes, an intensive dark green coloration develops, while the sodium dissolves. The reaction is completed after a period of time ranging between 30 and 60 minutes. 

Irradiation of 1-benzothiepins 1 in tetrahydrofuran with a high-pressure 450-W mercury lamp and a Pyrex filter at 0"C for four hours results in a reversal of the thiepin-synthesis method startingfrom 3,4-benzo-2-thiabicyclo[3.2.0]hept-3,6-dienes (see Section 2.1.3.3.), giving the photoproducts 2 along with some of the corresponding naphthalenes.1019... 

Let us discuss now the conditions required for the electron transfer process. This reaction requires, of course, a suitable electron donor (a species characterized by a low ionization potential) and a proper electron acceptor, e.g., a monomer characterized by a high electron affinity. Furthermore, the nature of the solvent is often critical for such a reaction. The solvation energy of ions contributes substantially to the heat of reaction, hence the reaction might occur in a strong solvating solvent, but its course may be reversed in a poorly solvating medium. A good example of this behavior is provided by the reaction Na -f- naphthalene -> Na+ + naphthalene". This reaction proceeds rapidly in tetrahydrofuran or in dimethoxy... 

Addition of styrene to a green solution of naphthalene" Na+ in tetrahydrofuran leads to an instantaneous change of color from green to red. Styrene polymerizes rapidly and quantitatively within a few seconds, and when the reaction is completed, addition of water converts the red solution of polystyryl carbanions into colorless solution of polystyrene. After precipitation of the polymer it was shown spectroscopically25 that the residual solution contains an amount of naphthalene equal to that used in the preparation of the initiating catalyst. This observation confirms the proposed mechanism of initiation of the polymerization. 

S-EED naphthalene-6-sulfonate 1,3-Benzene dicarboxamide THF heptane dionato) Tetrahydrofuran... 

The naphthalene extraction experiment was carried out under similar conditions except that nitrogen was used as cover gas instead of deuterium. The spent naphthalene-d8 was separated from the residue by distillation at reduced pressure. The residue was solvent fractionated with tetrahydrofuran (J. T. Baker Chemical Co.). 

The coal residue was separated into a THF-soluble fraction and a THF-insoluble residue. The wt % yields and atom % 2H compositions are given in Table I. The coal residue was 6 wt % soluble in tetrahydrofuran. The soluble fraction had 23 atom % 2H content. Evaluation of the 2H NMR data showed that 85 wt % of this fraction was derived from the coal and that its deuterium content was 10%. The chemically-bonded naphthalene-d8 content of the THF-soluble fraction, estimated from the 2H NMR data, was about 15 wt % or approximately 1 wt % of the coal. The insoluble residue had 6 atom % 2H content. This indicates that the residue contained approximately 1 wt % chemically-bonded naphthalene which was estimated from the difference in the atom % 2H content of the insoluble residue and recovered naphthalene-d8. This gives a total chemically-bonded naphthalene-d8 content of approximately 2 wt %. Similar results were obtained in extraction experiments made with phenanthrene (30), where it was found that 3-7 wt % of the phenanthrene was chemically linked to the coal product. 

Solvents. water was doubly-distilled from an all-Pyrex apparatus. All the other solvents were supplied by BDH and mostly used as supplied, except that tetrahydrofuran (THF) was first distilled from lithium "aluminium hydride and then from a sodium/naphthalene mixture (the green coloration of the latter being indicative of the absence of water). 

DMA in 500 ml ether mix rapidly with 270 ml 0.9 M phenyl-Li, boil fifteen hours and extract as for (VI) or as described previously to get 8 g oily 4-methoxy-indoline (or its 1-methyl derivative) (VII). Alternatively, add 36 g naphthalene to 300 ml tetrahydrofuran and add 11 g Na metal cut in small pieces. Reflux and stir three hours and add 18 g (VI) and 8 g DEA in 200 ml tetrahydrofuran rapidly and boil twelve hours. Evaporate in vacuum, dissolve the oily residue in 2N HCI and extract with ether. Proceed as described to get (VII). 4 g (VII) in 200 ml dry pyridine add to 6 g Cu chloride in 400 ml pyridine and reflux 1 xh hours. Pour on water and extract with ether. Wash extract with 4N HCI and then water and dry and evaporate in vacuum the ether to get 2 g of the indole (VIII). Alternatively, dissolve 4 g (VII) and 9.5 g cinnamic acid in 700 ml mesitylene, add 1 g 5% palladium-carbon and reflux five hours. Filter, wash with HCI and NaHC03 and dry and evaporate in vacuum the mesitylene to get the red, oily (VIII) (can chromatograph on alumina and elute with benzene-petroleum ether). 

Some alkali metal complexes are also capable of initiating anionic polymerisation. For example, sodium and naphthalene in tetrahydrofuran is a homogeneous solution initiates polymerisation as follows ... 

Highly reactive calcium can be readily prepared by the reduction of calcium halides in tetrahydrofuran solution with preformed lithium biphenylide under an argon atmosphere at room temperature.5 This colored calcium species seems to be reasonably soluble in THF. However, the reactive calcium complex prepared from preformed lithium naphthalenide was insoluble in THF solution and precipitated out of solution to give a highly reactive black solid. The exact nature of this black calcium complex has not been determined. Acid hydrolysis of the black material releases naphthalene as well as THF. Accordingly, the most likely structure of the black material is a Ca-naphthalene-THF complex similar in nature to the soluble magnesium-anthracene complex recently reported.6... 

Styrene, benzene, and tetrahydrofuran were purified as described previously (8,11). Solutions of ec-butyllithium (Lithium Corporation of America, 12.0 wt % in cyclohexane) and methyllithium (Alfa, 1.45 M in ether) and lithium naphthalene were analyzed using the double titration procedure with 1,2-dibromoethane (12). Lithium naphthalene was prepared in tetrahydrofuran from lithium metal and a 25 mole % excess of sublimed naphthalene at -25°C using standard high vacuum procedures. Sealed ampoules of lithium naphthalene were stored in liquid nitrogen. 

Naphthalene-based bifunctional Lewis acids that involve boron and a heavier group 13 element have also been prepared starting from the boron/tin derivative 30 (Scheme 15). Thus, the transmetalation reaction of 30 with gallium trichloride or indium trichloride in tetrahydrofuran (THF) results in high yields of l-(dichlorogallium)-8-(dimesitylboron)naphthalenediyl 35 and l-(dichloroindium)-8-(dimesitylboron)... 

Cleavage of the sulfonyl esters to the parent alcohols is accomplished in yields of 60-100% by treatment of the p-toluenesulfonates with 2-6 equivalents of sodium naphthalene in tetrahydrofuran at room temperature (yields 60-100%). Sodium naphthalene is prepared by stirring sodium with an equivalent amount or a slight excess of naphthalene in tetrahydrofuran for 1 hour at room temperature under an inert gas [701]. Benzenesulfonates and bromo-benzenesulfonates are also cleaved to the parent alcohols while alkyl methanesulfonates are reduced also to hydrocarbons [701]. 

Tetrahydrofuran itself can be opened using either the stoichiometric or the catalytic version of arene-promoted lithiation, but both cases need the activation by boron trifluoride. The catalytic reaction was performed by treating the solvent THF 324 with the complex boron trifluoride-etherate and a catalytic amount (4%) of naphthalene. The intermediate 325 was formed. Further reaction with carbonyl compounds and flnal hydrolysis yielded the expected 1,5-diols 326 (Scheme 95), which could be easily cyclized to the corresponding substituted tetrahydropyrans under acidic conditions (concentrated FlCl). 

The propagation rate constant and the polymerization rate for anionic polymerization are dramatically affected by the nature of both the solvent and the counterion. Thus the data in Table 5-10 show the pronounced effect of solvent in the polymerization of styrene by sodium naphthalene (3 x 1CT3 M) at 25°C. The apparent propagation rate constant is increased by 2 and 3 orders of magnitude in tetrahydrofuran and 1,2-dimethoxyethane, respectively, compared to the rate constants in benzene and dioxane. The polymerization is much faster in the more polar solvents. That the dielectric constant is not a quantitative measure of solvating power is shown by the higher rate in 1,2-dimethoxyethane (DME) compared to tetrahydrofuran (THF). The faster rate in DME may be due to a specific solvation effect arising from the presence of two ether functions in the same molecule. 

The sodium naphthalene polymerization of methyl methacrylate is carried out in benzene and tetrahydrofuran solutions. Which solution will yield the highest polymerization rate Discuss the effect of solvent on the relative concentrations of the different types of propagating centers. 

Assume that 1.0 x 10-3 mol of sodium naphthalene is dissolved in tetrahydrofuran and then 2.0 mol of styrene is introduced into the system by a rapid injection technique. The final total volume of the solution is 1 liter. Assume that the injection of styrene results in instantaneous homogeneous mixing. It is found that half of the monomer is polymerized in 2000 s. Calculate the propagation rate constant. Calculate the degree of polymerization at 2000 and at 4000 s of reaction time. 

A 1.5 M solution of styrene in tetrahydrofuran is polymerized at 25°C by sodium naphthalene at a concentration of 3.2 x 10 5 M. Calculate the polymerization rate and degree of polymerization using appropriate data from Table 5-11. What fractions of the polymerization rate are due to free ions and ion pairs, respectively Repeat the calculations for 3.2 x 10-2 M sodium naphthalene. 

In polar and H-bonding solvents such as acetone, tetrahydrofuran or methanol CgQ is essentially insoluble. It is sparingly soluble in alkanes, with the solubility increasing with the number of atoms. In aromatic solvents and in carbon disulfide, in general appreciable solubilities are observed. A significant increase of the solubility takes place on going from benzenes to naphthalenes. Although there are trends for the solution behavior of Cjq, there is no direct dependence of the solubility on a certain solvent parameter like the index of refraction n. When the solubility is... 

The chemical removal of water can be done in several ways. For anionic polymerisations it is customary to rinse all the glassware repeatedly with a solution of sodium naphthalide which reacts with water to form naphthalene and NaOH, both of which are adequately soluble in the usual solvent tetrahydrofuran (THF) at the low concentrations used. This method, however, requires that the whole reactor assembly be detachable from the vacuum line so that it can be tilted around for the sodium naphtalide solution to reach all parts of the system. Care If much water is to be removed and the volume of the purging solution is too small, some NaOH may be precipitated ). 

Metalation of Naphthalene by Potassium in Tetrahydrofuran at Room Temperature... 

Naphthalene is known to form a stable lithium dianion at -80°C in tetrahydrofuran (THP) at concentrations lower than 0.5 mol.I-1 (9-12). Unfortunately organolithium compounds are unable to polymerize oxirane (13). Naphthalene can also be metalation by sodium and potassium in THF but no experimental evidence for a dianion of naphthalene sodium or potassium is to be found. Although naphthalene metalation by sodium is thoroughly described ( , lU, 15), very few results about potassium are published (l6, "nT As the reducing power of the alkali metals decreases from lithium (Li/Li+ = 3 02v) to potassium (K/K+ -2.92v) and finally to sodium (Na/Na+ = 2.71v) (l8), it is attractive to study in more detail the naphthalene metalation by in the THF. 

Koton, et al. (7 8) have studied the acrolein propagation initiated by Na-Naphthalene complex or by t-butyllithium in tetrahydrofuran (THF) at various temperatures. From these results, a mechanism has been deduced, but it ignores the transfer reactions and the different complexations of the living end. 

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