Sodium, reaction tetrahydrofuran

Sodium tetrahydrogenaluminate was prepared by the action of hydrogen on a suspension of aluminium and sodium in tetrahydrofuran. A detonation caused by the following reaction interrupted the handling ... 

Dienes react quite readily with alkylbenzenes to form monoalkenylbenzenes under controlled experimental conditions. Sodium and potassium deposited on calcium oxide were found to be very suitable catalysts for these alkenylation reactions.240 Naphthalene-sodium in tetrahydrofuran is a very effective catalyst... 

The reaction of hexaphenyldilead with lithium metal proceeds well under mild conditions in tetrahydrofuran to form triphenylplumbyllithium free of major impurities 305>. Triphenylplumbylsodium has been prepared similarly from hexaphenyldilead and sodium in tetrahydrofuran 323) and in ammonia 137>. Triphenylplumbyl derivatives of the other alkali... 

Dianions of quinazoline, 2- and 4-phenylquinazoline, ° and 2,4-diphenylquinazoline, obtained by the reaction of the respective quinazolines with sodium in tetrahydrofuran, react with alkyl halides to give different alkylated dihydroquinazolines. Thus, a monomeric dianion of 4-phenylquinazoline affords, on alkylation with iodomethane, three dimethyldihydroquina-zolines including one in which the alkylation occurs in the benzo ring. ... 

Dicyclopentadienyl manganese was first obtained by thermal decomposition of the ammine [MnfNHsle] (CbHb)2 (50, 111). Shortly afterward, it was made in good yield by the reaction between manganese bromide and cyclopentadienyl sodium in tetrahydrofuran (214), and it may also be prepared by the interaction of manganese chloride and an ethereal solution of the Grignard reagent, followed by sublimation (60). At ordinary temperatures it forms brown crystals. 

In reductive acylation and dimerization, the cathode is often superior to dissolving metal or radical anions reductants. So a, j6-unsaturated ketones or esters can be acylated in high yield to 1,4-dicarbonyl compounds at the mercury cathode [39], but the corresponding reaction with sodium in tetrahydrofuran (THE) fails [40]. On the other hand, reductive acylation of double bonds becomes possible in high yield, when vitamin Bj2 is used as mediator [41]. Here cobalt-alkyl complexes play a decisive role as intermediates. 

Dihydroquinazolines are in equilibrium with 3,4-dihydroquinazolines, which are generally thermodynamically more stable. In order to obtain 1,4-dihydroquinazoIines it is necessary to have a substituent at N-1 so as to freeze the tautomerism. The proportion of l//-l,4-hydroquinazoline produced in a kinetically controlled reaction can, however, be appreciable. This is demonstrated in the following reactions. 4-Phenylquinazoline was reduced with sodium in tetrahydrofuran to the monomeric dianion. When the dianion was treated with water or one equivalent of methyl iodide, only 4-phenyl- and 4-methyl-4-phenyl- 3,4-dihydroquinazolines were isolated. If, however, two molecular equivalents of methyl iodide were added, a mixture of 1,4-dimethy 1-4-phenyl- (16%) and 3,4-dimethyl-4-phenyl- (42%) 3,4-dihydroquinazolines was formed. The monomeric dianion of 2,4-diphen-ylquinazoline gave l,4-dimethyl-2,4-diphenyl- and 3,4-dimethyl-2,4-diphen-yl-3,4-dihydroquinazoline in 60% and 27% yields, respectively, with methyl iodide. If ethyl chloroformate was used as alkylating agent, on the other hand, an 85% yield of l,4-bisethoxycarbonyl-2,4-diphenyl-3,4-dihydroquin-azoline was formed. A similar behavior was observed when methyl lithium reacted with 2,4-diphenylquinazoline followed by methylation of the intermediate lithium salts [Eq. (8)]. ... 

MAGNESIUM CHLORIDE (7786-30-3) Violent reaction or ignition with bromine penta-fluoride. oxygen difluoride, potassium, potassium-sodium alloy, tetrahydrofuran. Incompatible with zinc. Reacts with water, evolving significant heat. Attacks steel in the presence of moisture. 

Reduction of quinoxaline with sodium in tetrahydrofuran, or elec-trochemically in an alkaline medium, gives 1,4-dihydroquinoxaline. This is described as a white, insoluble compound of m.p. 158-159°, and it is thought to be a 1,4- rather than a 1,2-dihydro compound because reaction with methyl magnesium iodide shows that it contains approximately 1.8 atoms of active hydrogen per molecule. 

Figure 10. Arrhenius plot of the rate constants for the transition from the contact to the solvent separated ion pair (kC8) and for the reverse reaction (k8C) (polystyrene sodium in tetrahydrofuran with addition of sodium ions) (10)...

In addition, other techniques have recently been developed, involving base activation in heterogeneous media particularly noteworthy are the sodiiun amide-sodium -butoxide-tetrahydrofuran system by Caubere and the carbon tetra-chloride-/-butanol-potassium hydroxide system by MeyersThese methods, however, do not require the presence of a catalyst for ion transport from one phase to the other, and cannot be classified as reactions carried on under PTC conditions. 

In the now-obsolete furfural process, furfural was decarboxylated to furan which was then hydrogenated to tetrahydrofuran (THF). Reaction of THF with hydrogen chloride produced dichlorobutene. Adiponitrile was produced by the reaction of sodium cyanide with the dichlorobutene. The overall yield from furfural to adiponitrile was around 75%. 

These reactions are usehil for the preparation of homogeneous difunctional initiators from a-methylstyrene in polar solvents such as tetrahydrofuran. Because of the low ceiling temperature of a-methylstyrene (T = 61° C) (26), dimers or tetramers can be formed depending on the alkaU metal system, temperature, and concentration. Thus the reduction of a-methylstyrene by sodium potassium alloy produces the dimeric dianionic initiators in THF (27), while the reduction with sodium metal forms the tetrameric dianions as the main products (28). The stmctures of the dimer and tetramer correspond to initial tail-to-tail addition to form the most stable dianion as shown in equations 6 and 7 (28). 

Under the best conditions, sodium cyclopentadienide gives pale yellow or orange solutions. Traces of air lead to red or purple solutions, as does insufficiently purified solvent, without, however, lowering the reaction yield appreciably. If 1,2-di-methoxyethane is used, in which sodium cyclopentadienide is less soluble than in tetrahydrofuran, white crystals may be obtained at this point. 

During one run, 48 g. of product precipitated from the tetrahydrofuran reaction mixture. This precipitate was filtered, washed with saturated, aqueous sodium chloride, water, and petroleum ether (b.p. 35-60°) to yield a crystalline product, m.p. 99-106°. For recovery of the remaining product, the tetrahydrofuran filtrate was worked up in accordance with the described procedure. 

The general reaction procedure and apparatus used are exactly as described in Procedure 2. Ammonia (465 ml) is distilled into a 2-liter reaction flask and to this is added 165mlofisopropylalcoholandasolutionof30g(0.195 mole) of 17/ -estradiol 3-methyl ether (mp 118.5-120°) in 180 ml of tetrahydrofuran. The steroid is only partially soluble in the mixture. A 5 g portion of sodium (26 g, 1.13 g-atoms total) is added to the stirred mixture and the solid dissolves in the light blue solution within several min. As additional metal is added, the mixture becomes dark blue and a solid (matted needles) separates. Stirring is inefficient for a few minutes until the mass of crystals breaks down. All of the sodium is consumed after 1 hr and 120 ml of methanol is then added to the mixture with care. The product is isolated as in Procedure 4h 2. After being air-dried, the solid weighs 32.5 g (ca. 100% for a monohydrate). A sample of the material is dried for analysis and analyzed as described in Procedure 2 enol ether, 91% unreduced aromatics, 0.3%. The crude product may be crystallized from acetone-water or preferably from hexane. 

While keeping the collected deuterioammonia at dry ice-isopropyl alcohol temperature, lithium wire (10 mg) is added, followed by a solution of 3/3-hydroxy-5a-cholest-7-en-6-one (161 50 mg) in anhydrous tetrahydrofuran (4 ml). The reaction mixture is stirred for 20 min, the cooling bath is then removed and the ammonia is allowed to boil under reflux for 40 min. A saturated solution of ammonium chloride in tetrahydrofuran is added dropwise until the deep blue color disappears and then the ammonia is allowed to evaporate. The residue is extracted with ether and the organic layer washed with dilute hydrochloric acid and sodium bicarbonate solution and then with water. Drying and evaporation of the solvent gives a semicrystalline residue which is dissolved in acetone and oxidized with 8 N chromic acid solution. After the usual workup the residue is dissolved in methanol containing sodium hydroxide (0.2 g) and heated under reflux for 1 hr to remove any deuterium introduced at C-5 or C-7. (For workup, see section II-B). 

A suspension of 17a,21-dihydroxypregna-4,9(ll)-diene-3,20-dione 21-acetate (0.77 g) and iV-bromoacetamide (0.3 g) in anhydrous methylene dichloride (40 ml) is added over 2-3 min with stirring to a mixture of anhydrous hydrogen fluoride (10.19 g), and anhydrous tetrahydrofuran (18 g) in a polyethylene bottle at —80° (acetone-dry ice). After 1 hr at —80° the reaction mixture is kept for a further 1 hr at 0° and then added cautiously to an excess of an ice-cold solution of sodium carbonate. Extraction with methylene dichloride and crystallization from acetone-hexane furnish 9a-bromo-ll -fluoro-17a,21-dihydroxypregn-4-ene-3,20-dione 21-acetate (0.69 g), mp 205-208°, raised by several crystallizations from acetone-hexane to 215-217° [aju 142° (CHCI3) max 240-242 mju (e 15,500). 

A solution of the monosodium salt of diacetylene in 300 ml of liquid ammonia is prepared from 13.8 g (0.6 g-atoms) sodium and 24.6 g (0.2 moles) l,4-dichlorobut-2-yne. To this mixture is added a suspension of 5 g (17.6 mmoles) 3-methoxyestra-l,3,5(10)-trien-17-one in anhydrous tetrahydrofuran at —40° and the reaction mixture is stirred and maintained at this temperature for 2 hr. Ammonium chloride is then added and the ammonia is allowed to evaporate overnight. The residual solids are extracted with methylene dichloride and the extracts washed with water, dried over magnesium sulfate, and evaporated at 70°. The resultant dark gum is... 

A-Fluoro-2,4,6-tnmethylpyndmium inflate (1 mmol) is added m several portions at room temperature to a tetrahydrofuran solution of sodium diethyl phenyl-malonate, obtained from 1 mmol of diethyl phenyl malonate and sodium hydnde at 0 C in tetrahydrofuran The reaction imxture is poured mto dilute hydrochlonc acid and extracted with ether The ether extract is washed with sodium bicarbonate and water and dned over magnesium sulfate The oily residue obtamed after removal of tihe ether is chromatographed on sihca gel (dichloromethane-hexane, 1 1) to give diethyl fluorophenylmalonate in 83% yield... 

The trialkylborane is oxidized by the addition to the stirred reaction mixture of 32 ml of a 3 solution of sodium hydroxide, followed by the dropwise addition of 32 ml of 30 % hydrogen peroxide at a temperature of 30-32° (water bath). The reaction mixture is saturated with sodium chloride and the tetrahydrofuran layer formed is separated and washed with saturated sodium chloride solution. The organic solution is dried over anhydrous magnesium sulfate and the THF is removed. Distillation affords 24.5 g (80%) of 4-methyl-1-pentanol, bp I51-153°/735 mm. 

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