Hydrolysis glycol synthesis

Other possible chemical synthesis routes for lactic acid include base-cataly2ed degradation of sugars oxidation of propylene glycol reaction of acetaldehyde, carbon monoxide, and water at elevated temperatures and pressures hydrolysis of chloropropionic acid (prepared by chlorination of propionic acid) nitric acid oxidation of propylene etc. None of these routes has led to a technically and economically viable process (6). 

Sugar is destroyed by pH extremes, and inadequate pH control can cause significant sucrose losses in sugar mills. Sucrose is one of the most acid-labile disaccharides known (27), and its hydrolysis to invert is readily catalyzed by heat and low pH prolonged exposure converts the monosaccharides to hydroxymethyl furfural, which has appHcations for synthesis of glycols, ethers, polymers, and pharmaceuticals (16,30). The molecular mechanism that occurs during acid hydrolysis operates, albeit slowly, as high as pH 8.5 (18). 

Iodosobenzene diacetate is used as a reagent for the preparation of glycol diacetates from olefins,9 for the oxidation of aromatic amines to corresponding azo compounds,10 for the ring acetylation of N-arylacetamides,11 for oxidation of some phenols to phenyl ethers,12 and as a coupling agent in the preparation of iodonium salts.13 Its hydrolysis to iodosobenzene constitutes the best synthesis of that compound.14... 

It has been pointed out that some important biomolecules have short half-lives at higher temperatures, as is clearly shown by laboratory experiments. The synthesis of adenine in the HCN oligomerisation demonstrated that chemical processes can also take place at lower temperatures. After hydrolysis of the oligomerisation products, adenine was isolated after 60-100 days from 0.01 M solutions at a pH of 9.2. Addition of glycol nitrile caused the yield to increase by a factor of four, i.e., to 48 pg/L (Schwartz et al., 1982). 

From a study of the fluoroacetates so far mentioned, it appears that any compound which can give rise to fluoroacetic acid (or the fluoroacetate ion), either by hydrolysis or by oxidation (or both), is toxic. The toxic grouping is thus F-CH2-CO, and any substitution in this radical destroys the toxicity as far as relatively simple compounds are concerned. We had reached this conclusion by May 1943.1 We subsequently showed that esters of / -fluoropropionic acid were non-toxic, whereas esters of y-fluorobutyric acid were shown by American workers to be toxic. In 19442 we reported the synthesis of ethyl 5-fluoro-pentanecarboxylate, F,[CH2]g C02Et (I). This is a stable, colourless liquid and we showed that it possessed very potent toxic properties of the fluoroacetate type. By subcutaneous injection of the propylene glycol solution into mice the l.d. 50 was 4 mg./kg. Methyl fluoroacetate (II) may be taken as a convenient standard (p. 115) and has a l.d. 50 of about 6 mg./kg. for saline solutions, and 15 mg./kg. for propylene glycol solution.3 Therefore ethyl 5-fluoropentanecarboxylate was about 7 times as toxic as methyl fluoroacetate (molecule for molecule).4... 

Bachman and co-workers ° studied the synthesis of the high explosive ethylenedinitrantine (2) (EDNA) from the hydrolysis of secondary nitramides. One of the oldest routes to EDNA (2) involves the nitration of 2-imidazolidone (66) with mixed acid, followed by hydrolysis of the resulting A,A -dinitro-2-imidazolidone (67) with boiling water. 2-Imidazolidone (66) is readily synthesized from the reaction of urea with ethylene glycol, or by treating either... 

The synthesis of bisantrene begins with Diels-Alder reaction of anthracene (52) and ethylene carbonate (53) to produce adduct 54. Hydrolysis and glycol cleavage lead to bls-carboxaldehyde 55. This readily forms a bis-hydrazone with guanylhydrazine [16]. 

A convenient synthesis of difluoroacetic acid (21) is found in first converting the amide 19 to the difluoro derivative 20 by potassium fluoride in ethylene glycol at 180,JC followed by hydrolysis.53... 

GRUNDMANN ALDEHYDE SYNTHESIS. Transformation of an acid into an aldehyde of the same chain length by conversion of the acid chloride via the diazo ketone to the acetoxy ketone, reduction with aluminum isopropoxide and hydrolysis to the glycol, and cleavage with lead tetraacetate. 

The electrochemical route (2) can be applied only for the synthesis of Bi(OMe)3, which is insoluble in the parent alcohol (in the other alcohols it was the electrochemical refinement of metal that took place) [967], The glycolates and derivatives of polyatomic phenols stable to hydrolysis have been obtained on alcoholysis ofBi203 [1808, 1352, 684, 559]. 

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