Sodium in ethylene glycol

Cyclohexyloxyethanol has also been prepared by reduction of cyclohexyloxyacetic acid with lithium aluminum hydride 8 and by decomposition of cyclohexanone methanesulfonylhydrazone with sodium in ethylene glycol.9... 

The reaction of tosylhydrazones with sodium in ethylene glycol to give alkenes had been observed before (Bamford-Stevens reaction) other bases, e.g. NaOMe, alkali metal hydrides and NaNH2 were also used. However, in these cases side reactions occur and, in contrast to the Shapiro reaction, the more highly substituted alkene is predominantly formed. Two mechanisms are discussed for these reactions a mechanism via a carbenium ion, which usually takes place in protic solvents, and a carbene mechanism in aprotic solvents (Scheme 28). In both cases diazo compounds are intermediates, which can sometimes be isolated. ... 

Other bases may be employed, e.g. lithium hydride, sodium hydride, sodium amide or sodium in ethylene glycol with sodium in ethylene glycol, the reaction is called the Bamford-Stevens reaction. Aldehyde tosylhydrazones (200) do not form dianions with organolithiums, but the reagent adds to the carbon-nitrogen double bond to give the dilithium derivative (201) which decomposes to the organolithium compound (202). 

The base-mediated conversion of arylsulfonylhydrazones to alkenes was first observed by Bamford and Stevens in 1952.6 In a representative transformation, tosylhydrazone 3 was converted to cyclohexene (4) in quantitative yield after refluxing for 90 minutes in an alkoxide solution derived from dissolution of sodium in ethylene glycol. These reactions are believed to proceed via intermediate diazo compounds, which are transformed to alkenes by thermal elimination processes. 

Syntheses of 4,5- and Other Unsaturated Cyclic Compounds - Tosylhydra-zones of a-oxycarbonyl compounds are readily converted into vinyl ethers with sodium in ethylene glycol (Bamford-Stevens elimination) as illustrated by the conversion of 47 to 48. ... 

Smith and co-workers utilized the Bamford-Stevens reaction en route to a total synthesis of echinosporin 51. Tosylhydrazone 49 was heated with sodium in ethylene glycol to afford key intermediate 50 on large scale. Dihydrofuran 50 was then taken through a further ten steps to afford echinosporin 51. 

Ji-Methoxy-ll, 11-ethylenedioxy-lS-methylestra-1,3,5(lO)-tnene. A solution of (+)3-methoxy-18-methylestra-l,3,5(10)-trien-17-one (5 g) dissolved in ethylene glycol (5 ml) and ethyl orthoformate (10 ml) containing />-toluenesulfonic acid (0.3 g) is heated under reflux for 2 hr in a nitrogen atmosphere. The resulting solution is diluted with methylene chloride and washed with dilute sodium bicarbonate and water. The organic phase is dried over sodium sulfate and evaporated to dryness in the presence of a trace of pyridine. Trituration of the residue with petroleum ether yields 4.7 g (82 %) of the pure ketal. 

For unsubstitUted or lower alkylated dioxotriazines, it is advantageous to cyclize semicarbazones by sodium ethylate in ethylene glycol as described by Chang and XJlbricht. In this reaction 6-aza-uracil is obtained in 66% yield. The procedure was used for the preparation of labeled 6-azauracil ° and later for the synthesis of a number of 6-alkyl derivatives including 6-azathymine. °... 

Soldered brass seldom gives trouble. In radiators, antifreeze solutions have been alleged to cause corrosion, possibly because materials such as ethylene glycol sometimes detach protective deposits. Sodium nitrite, valuable as a corrosion inhibitor for other metals in a radiator, tends to attack solders, but sodium benzoate is safe and, in addition, protects the soldered joint against the action of nitrites. In an investigation of other inhibitors in ethylene glycol solutions, 1% borax, either alone or in combination with 0-1% mercaptobenzothiazole, appeared to be satisfactory. 

Cyclohexadiene has been prepared by dehydration of cyclohexen-3-ol,3 by pyrolysis at 540° of the diacetate of cyclohexane-1,2-diol,4 by dehydrobromination with quinoline of 3-hromocyclohexene,6 by treating the ethyl ether of cyclohexen-3-ol with potassium bisulfatc,6 7 by heating cyclohexene oxide with phthalic anhydride,8 by treating cyclohexane-1,2-diol with concentrated sulfuric acid,9 by treatment of 1,2-dibromocyclo-hexane with tributylamine,10 with sodium hydroxide in ethylene glycol,10 and with quinoline,6 and by treatment of 3,6-dibromo-cyclohexene with sodium.6... 

Hydrolysis of PET with Sodium Hydroxide in Ethylene Glycol... 

Example 2. Reactor Experiment.66 Waste PET (110 g), 800 g of ethylene glycol, and 93 g of 50% aqueous sodium hydroxide were introduced into a reactor. The reaction mixture was heated to 170° C with agitation while collecting distillate (mostly water with some ethylene glycol). The slurry, which consisted of disodium terephthalate in ethylene glycol, was filtered at a temperature of 170° C in a vacuum filter. The disodium terephthalate obtained was pressed as dry as possible and the ethylene glycol was recovered. The filter cake was washed with room temperature EG to remove impurities and to cool the disodium terephthalate to less than 100° C, followed by washing with a saturated solution of disodium terephthalate in water (maintained at 90-100° C). 

A method of converting polycarbonate (PC) to bishydroxyethyl ether of bisphenol A (BHE-BPA) was studied, with a view to recycling PC plastic wastes. Treating PC in ethylene glycol with a catalytic amount of sodium hydroxide produced the monohydroxyethyl ether of bisphenol A (MHE-BPA, 42%), BHE-BPA (11%) and BPA (42%). BHE-BPA was produced quantitatively when 1.6 mol. equiv. ethylene carbonate was added to this reaction system. The reaction of BPA with EC produced both BHE-BPA and MHE-BPA, indicating that ethylene carbonate was formed as an intermediate in the base catalysed reaction of PC with ethylene glycol. A large proportion of this ethylene carbonate formed from PC was, however, lost by decarboxylation so additional ethylene carbonate must be provided for the quantitative preparation of BHE-BPA. 12 refs. 

Coburn also reported the synthesis of BPAF (41), the 3,4-bis-picrylamino derivative of furazan. Thus, reaction of two equivalents of aniline with 1,2-dichloroglyoxime (38) yields the bis-aniline (39), which on treatment with sodium hydroxide in ethylene glycol undergoes cyclization to the furazan (40), and nitration of the latter with concentrated nitric acid at room temperature yields BPAF (41). 

Wilier synthesized the bis-nitramine (51) via the cyclodehydration of the dioxime (49) with sodium hydroxide in ethylene glycol followed by subsequent nitration of the resulting heterocycle (50). 

The partial reduction of benzofuroxans, discussed in Section 4.05.5.2.4, represents an effective route to numerous benzofurazans. The conversion may be achieved either directly by deoxygention, for example, with sodium azide in ethylene glycol or acetic acid <75Ci(M)243> or using phosphites, or in two stages via the dioxime with subsequent dehydration as described above. 

The product hydrazide may be sulfonated and decomposed by heating with a base in ethylene glycol to yield benzaldehyde, CeHsCHO. Many aromatic aldehydes may be produced by similar routes. The hydrazone derivative of toluenesulfonic acid reacts with an aldehyde or a ketone in the presence of a base catalyst, such as sodium ethoxide, to yield the corresponding olefin (Bamford-Stevens reaction) ... 

Treatment of MFA (1) with cyanogen bromide [6] opened ring G to yield the bromo derivative 3 [7]. Attempts to dehydrobrominate 3 in one step via a base-catalyzed elimination with DBU/CH3CN, KOH/MeOH, or terr-BuOK/DMSO were unsuccessful. However, the required methylene entity could be introduced by converting 3 first to a selenide, then oxidation with periodate, followed by thermolysis in benzene to provide compound 4. Hydrolysis of the cyano group with NaOH in ethylene glycol [8] produced 5 (50% yield). Osmium catalyzed oxidation of 5 in the presence of 4-methylmorpholine A-oxide (NMO) gave a diol, which was cleaved to an aldehyde upon treatment with periodate. Treatment of the aldehyde with sodium cyanoborohydride resulted in an intramolecular reductive animation to yield the desired product PHB (6). 

Sodium metal was dissolved in ethylene glycol and a solution of 37 in toluene was added. The mixture was heated at 100 °C and a 98% yield of the free base 3 was obtained. The free base was treated with fumaric acid in ethanol and 3 was isolated as the crystalline fumarate salt in 85% yield. 

FORMATION OF DIAZO COMPOUNDS BY PYROLYSIS OF SODIUM SALTS OF TOSYLHYDRAZONES IN ETHYLENE GLYCOL... 

Sodium hypophosphite monohydrate [10039-56-2J M 106.0. Dissolve in boiling EtOH, cool and add dry Et20 till all the salt separates. Collect and dry in vacuum. It is soluble in 1 part of H2O. It liberates PH3 on heating and can ignite spontaneously when heated. The anhydrous salt is soluble in ethylene glycol (33% w/w) and propylene glycol (9.7%) at 25°. 

Phenyldiazomethane, 1, 834. A new method for preparation of this (and other aryl-diazomethanes) involves a vacuum pyrolysis of the sodium salt of benzaldehyde tosylhydrazone, a method introduced for carrying out the Bamford-Stevens reaction. The yield is 80%, the highest yield yet reported. Another advantage is that the reagent is obtained free from solvents. The pyrolysis can also be coitducted in ethylene glycol at 80° with extraction of the aryldiazomethane into hexane.1 Caution All diazo compounds arc highly toxic and potentially explosive. 

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