Chlorophenyl acetate, hydrolysis

Chemical/Physical. May degrade to bis(chlorophenyl)acetic acid in water (quoted, Verschueren, 1983), or oxidize to jo,//-dichlorobenzophenone using UV light as a catalyst (HSDB, 1989). p,//-DDE is resistant to hydrolysis. At pH 5 and 27 °C, the estimated half-life is >120 yr (Wolfe et al., 1977). This is in agreement with results reported by Eichelberger and Lichtenberg (1971). They found no change in jo,//-DDE concentration in water in an 8-wk period. 

Di-(p- chlorophenyl)-acetic acid is prepared in 70% yield from l,l-di-(p-chlorophenyl)-2,2,2-trichloroethane, (p-ClC H4)jCHCClj (DDT). This reaction differs from a straightforward hydrolysis since hydrogen chloride is eliminated and an intermediate, l,l-di-(p-chlorophenyl)-2,2-dichloroethyl-ene, (p-ClCgH4)2C = CClj, is readily isolated in 97% yield. ... 

Metabolism of DDT proceeds at a very slow rate. Liver microsomal P450 and other microsomal enzymes initially dechlorinate DDT to l,l-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and reduce to 1,1 -dichloro-2,2-bis(p-chlorophenyl)ethane (DDD). The conversion of DDD to bis(p-chlorophenyl)acetic acid (DDA) involves the formation of an acyl chloride intermediate by hydroxylation followed by hydrolysis to yield the final product. 

The 6//-l,3-thiazin-6-iminium hydroperchlorate salts 78-81 give interesting products when treated with nucleophiles <2003H(60)2273>. Hydrolysis of 6-imino-6//-l,3-thiazine hydroperchlorate 78 affords (2Z,4Z)-2-cyano-5-hydroxy-5-phenyM-azapenta-2,4-dienethioamide 82 in excellent yield, while treatment with morpholine gives 2-(morpholinomethylene)malononitrile 83 and thiobenzamide. The 5-(ethoxycarbonyl) -(methylthio)-2-aryl-6/7-l,3-thiazin-6-iminium salts 79 and 80 react with hydroxide or morpholine to afford ethyl 4-(methylthio)-2-aryl-6-thioxo-l,6-dihydropyrimidine-5-carboxylates 84 and 85. In the case of the 4-chloro analogue 80, the (Z)-ethyl 2-(5-(4-chlorophenyl)-37/-l,2,4-dithiazol-3-ylidene)-2-cyanoacetate 87 is also formed for the reaction with sodium hydroxide. The 1,2,4-dithiazoles 86 and 87 can be obtained as the sole product when 79 and 80 are treated with sodium acetate in DMSO. Benzoxazine 88 is isolated when the iminium salt 81 is treated with morpholine or triethylamine. Nitrile 89 is formed as a ( /Z)-mixture when 6-imino-67/-l,3-thiazine hydroperchlorate 79 is reacted with triethylamine and iodomethane in methanol <2003H(60)2273>. 

The rate of hydrolysis of a carboxylic ester in strong sulphuric acid generally shows one of the three types of dependence on acid concentration illustrated in Fig. 1. The simplest behaviour, a continuous increase in hydrolysis rate with increasing acid concentration, is shown by esters of tertiary alcohols, which are hydrolyzed very rapidly even in moderately concentrated acid, and by phenol esters, which are somewhat less reactive, but are hydrolyzed much faster than esters of simple primary and secondary alcohols with above about 60% H2S04. Substituted phenyl acetates behave very much like the parent compound, the p-chlorophenyl ester being hydrolyzed at almost the same rate as the unsubstituted compound, while p-nitrophenyl acetate is somewhat less reactive at low acid concentrations, but more reactive in above 70% sulphuric acid. 

It has been shown that 1,6-a.nhydro-L-gIycero-D-manno-heptopyreinose is one of the products formed on acidic hydrolysis or methanolysis of an i.-glycero-D-/77a o-heptose-containing polysaccharide from Bordetella pertussis endotoxin. Alkaline treatment of 2-chlorophenyl j6-maltotrioside deca-acetate afforded l,6-anhydro-j3-maltotrioside, which was isolated as the crystalline nona-acetate. ... 

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