Chloroacetate group

P212121 Z = 4 Dx = 1.25 R = 0.066 for 1,234 intensities. The conformation of the septanose is a 5,6C2 (d) twist-chair. Both dioxolane rings are envelopes, 2E (17°) and lE (16°). The chloroacetate group is almost planar, with the largest deviation (of 11°) in the C-7-0-5 torsion-angle. There is no hydrogen-bonding, which accounts for the relatively low density. 

For the synthesis of Olivomycin A. the Roush group used a crotyl ether to protect a phenolic hydroxyl group,42 In the final lap of the synthesis, deprotection of the phenolic crotyl ether in 226.1 was achieved with Pd(0) and tributylstan-nane [Scheme 4.226]. No harm befell the sensitive cyclopentylidene acetal and chloroacetate groups. 

The grafting from technique can also provide a route to graft copolymers via ATRP. Matyjaszewski et al. used a poly [(vinyl chloride)-co-(vinyl chloroace-tate)] copolymer, containing about 1% of the chloroacetate groups, to initiate the ATRP of St, MA, nBA, and MMA, resulting in graft copolymers with well-defined graft units(Scheme 43) [297]. 

The best-established electron-capture-GLC method for plasma testosterone is that of Brownie et al. (B22) and is very similar in principle to that already described for progesterone (V2). Another is described by Kirschner and Coffman (K6). The latter paper uses the enzymatic conversion of androstenedione to testosterone and the use of heptafluoro-butyrate radicals in place of the chloroacetate group used originally by Brownie et al. (B22 see also V4). 

It is also possible to convert carbonyl groups into oxirane rings with cenain carbenoid synthons. The classical Darzens reaction, which involves addition of anions of a-chloroacetic esters, has been replaced by the addition of sulfonium ylides (R. Sowada, 1971 C.R. Johnson, 1979). 

In 1880, Liebermann and Voltzkow (40), and then Voltzkow (41), condensing chloroacetic acid with both ethyl N-phenylthiocarbamate and p-tolylisothiocyanate obtained homologous compounds to which they attributed formulas 40 and 41, whereas their structure probably derives from that of 38 by substituting an aryl group on the cyclic nitrogen. 

Chemical Properties and Industrial Uses. Chloroacetic acid has wide appHcations as an industrial chemical intermediate. Both the carboxyhc acid group and the cx-chlorine are very reactive. It readily forms esters and amides, and can undergo a variety of cx-chlorine substitutions. 

A solution of sodium cyanide [143-33-9] (ca 25%) in water is heated to 65—70°C in a stainless steel reaction vessel. An aqueous solution of sodium chloroacetate [3926-62-3] is then added slowly with stirring. The temperature must not exceed 90°C. Stirring is maintained at this temperature for one hour. Particular care must be taken to ensure that the hydrogen cyanide, which is formed continuously in small amounts, is trapped and neutrali2ed. The solution of sodium cyanoacetate [1071 -36-9] is concentrated by evaporation under vacuum and then transferred to a glass-lined reaction vessel for hydrolysis of the cyano group and esterification. The alcohol and mineral acid (weight ratio 1 2 to 1 3) are introduced in such a manner that the temperature does not rise above 60—80°C. For each mole of ester, ca 1.2 moles of alcohol are added. 

This ester was designed as a protective group for the 2-position in glycosyl donors. It has the stability of the benzoate during glycosylation, but has the ease of removal of the chloroacetate. It is readily introduced through the acid chloride... 

Aryl-6-carboethoxy(and 6-carboxy)-4-oxo-2-thioxo-l,3,8-triaza-naphthalenes are converted (100°, 3 hr) 7 7 7b to 2-oxo compounds with chloroacetic acid (cf. 136 and 237). The 4-oxo group is replaced (96°, 1 hr) by hydrazine along with ring-closure involving the 6-carboethoxy group in the 2-thioxo compounds, this substituent is simultaneously converted to an oxo group. 

Hydroxy group of 8-hydroxy-3-(4-methoxyphenylmethyl)-2-[4-(l-rerr-butoxycarbonyl-4-piperidinyl)butyl]perhydropyrido[l,2-a]pyrazine was alkylated with /err-butyl chloroacetate (00JAP(K)00/86659). 

An aqueous solution containing 0.10 mole/liter of chloroacetic acid, ClH2CCOOH, is tested with indicators and the concentration of H (aq) is found to be 1.2 X 10 2 M. Calculate the value of Ka (if necessary, refer back to Section 11-3.2). Compare this value with KA for acetic acid—the change is caused by the substitution of a halogen atom near a carboxylic acid group. 

Many polyazamacrocycles have been alkylated with chloroacetic acid leading to compounds which contain both amine and carboxylic acid functions, e.g. [63] (Stetter et al., 1981). These compounds are similar to EDTA (ethylenediamine tetraacetate). Although the ring size of this class of macrocycles and the number of N—CH2—COOH groups has been modified... 

B. Reactions.—(/) Halides. Whereas ylides are alkylated in the normal way on treatment with a-bromo- or a-iodo-esters, quite different reactions occur with a-fluoro- and a-chloro-acetates. When salt-free ylides were refluxed in benzene with ethyl fluoroacetate or trifluoroacetate normal Wittig olefin synthesis took place with the carbonyls of the ester groups to give vinyl ethers, e.g. (14). On the other hand, methyl chloroacetate with... 

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