Monochloroacetic acid formation

Electrochemical reduction in aqueous acid is useful in the treatment of waste liquors obtained from the formation of chloroacetic acid by chlorination of acetic acid. The liquors contain further chlorination products. These are reduced in an undivided cell at a magnetite cathode and a carbon anode to give excellent conversion to monochloroacetic acid [73]. 

Instead of monochloroacetic acid, the condensation with a primary amine can be done using methyl bromoacetate. This procedure was used for the syntheses of /J-methoxyethyliminodiacetic acid /J-methoxyethylamine, methyl bromoacetate and potassium carbonate were reacted without solvent with formation of the corresponding ester (equation 6). This was separated, purified by distillation and hydrolyzed with a Ba(OH)2 solution. The separation of the acid from die solution was made after quantitative removal of barium ions with sulfuric acid.10... 

A look at the mechanism (page 98) shows that DCC—in order to be attacked by DMSO needs to be activated by protonation. On the other hand, the reaction fails in the presence of a strong acid, such as HC1, H2SO4 or HCIO4, because these would prevent the formation of the sulfur ylide.11 Moffatt et al. found that the oxidation of testosterone (14) succeeds using mild acids with pKa inside a narrow window.14a For example, no oxidation occurs with acetic acid (pKa = 4.76) or trichloroacetic acid (pKa = 0.66), because their pKas lay outside the acidity window, while monochloroacetic acid (pKa = 2.86) leads to a slow and incomplete reaction, and dichloroacetic acid (pKa = 1.25) produces a quantitative oxidation in ten minutes. 

Investigation into the formation of carboxymethyl ethers of polysaccharides has continued, on account of the great utility of these derivatives as ion-exchange materials and polyelectrolytes. As expected, a whole series of polysaccharide derivatives of different degrees of substitution can be prepared by variation of the reaction conditions and molar proportions of monochloroacetic acid. " Published reports include the preparation of various carboxymethyl ethers of starches, amyloses, lichenan, pachymans, and chitin and introduction of the carboxymethyl group into polysaccharide derivatives constitutes a useful way of raising their solubility in water. By combining the introduction of alkyl and carboxy-... 

Aryl halides are frequently prepared from the corresponding aryldiazonium salts by diazotation procedures. However, diazonium salts can be subjected directly to very mild Heck arylation conditions, which deliver coupled products (entry 19). Preferably, the reaction is executed in nonaqueous solvents such as acetonitrile, acetone, or methylene chloride with sodium acetate as base and with palladiumbis(dibenzylideneacetone) as catalyst. Alternatively, a combination of the amine and f-butyl nitrite, in a mixture of acetic acid and monochloroacetic acid, can provide the desired product directly, which makes the isolation of a diazonium salt unnecessary (entry 20). " It is also possible to use aromatic acid anhydrides as oxidative addition precursors (entry 21). Clearly, anhydrides are very interesting starting materials for a number of Heck reactions due to price and absence of halide salt formation. 

Several reports concern the formation of organic ligand complexes of iron(iii). The variation of rate with ligand concentration in the reaction with mandelic acid > is interpreted as a pre-equilibrium ion-pair formation followed by dissociative complex formation within the ion-pair, rather than as simple 5 n2 formation. This interpretation is similar to that proffered for formation of malonate and oxalate complexes of chromium(iii) (see above). Rates of reaction of iron(iii) with a variety of phenols are all very similar, suggesting that iron(iii)-water bond breaking is rate determining here also. Sulphosalicylate reacts with FeOH + by the same rate-determining loss of water from the iron(m). Rates of formation of iron(iii) complexes with acetate, monochloroacetate, and propionate have been reported. ... 

The alkylation of phenolates with monochloroacetic add, leading to the formation of corresponding aryloxyacetic acids, can be used if a larger amount (0.1 —0.2 g) of phenol is available. The advantage of these deriva-... 

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