Chloroacetic anhydride

Much of the chloroacetyl chloride produced is used captively as a reactive intermediate. It is useful in many acylation reactions and in the production of adrenalin [51-43-4] diazepam [439-15-5] chloroacetophenone [532-27-4] chloroacetate esters, and chloroacetic anhydride [541-88-8]. A major use is in the production of chloroacetamide herbicides (3) such as alachlor [15972-60-8]. 

Production of cellulose esters from aromatic acids has not been commercialized because of unfavorable economics. These esters are usually prepared from highly reactive regenerated cellulose, and their physical properties do not differ markedly from cellulose esters prepared from the more readily available aHphatic acids. Benzoate esters have been prepared from regenerated cellulose with benzoyl chloride in pyridine—nitrobenzene (27) or benzene (28). These benzoate esters are soluble in common organic solvents such as acetone or chloroform. Benzoate esters, as well as the nitrochloro-, and methoxy-substituted benzoates, have been prepared from cellulose with the appropriate aromatic acid and chloroacetic anhydride as the impelling agent and magnesium perchlorate as the catalyst (29). 

Scheme 6 depicts a typical penicillin sulfoxide rearrangement (69JA1401). The mechanism probably involves an initial thermal formation of a sulfenic acid which is trapped by the acetic anhydride as the mixed sulfenic-acetic anhydride. Nucleophilic attack by the double bond on the sulfur leads to an episulfonium ion which, depending on the site of acetate attack, can afford either the penam (19) or the cepham (20). Product ratios are dependent on reaction conditions. For example, in another related study acetic anhydride gave predominantly the penam product, while chloroacetic anhydride gave the cepham product (7lJCS(O3540). The rearrangement can also be effected by acid in this case the principal products are the cepham (21) and the cephem (22 Scheme 7). Since these early studies a wide variety of reagents have been found to catalyze the conversion of a penicillin sulfoxide to the cepham/cephem ring system (e.g. 77JOC2887).

Recently, an analogous meso-ionic l,3-diazol-4-one (93b) was unexpectedly encountered as the product of the reaction between 1-azaphenothiazine and chloroacetic anhydride. 

Chloroacetyl chloride and 2-bromoacetyl bromide N-acylated without a catalyst but 2-chloroacetic anhydride required concentrated sulfuric acid. ° 3-Chloro- and 3-bromopropionyl chlorides 9-acyl-ated without a catalyst as did cinnamoyl chloride " and phosgene, the last producing 9-chloroformyIcarbazole. ... 

An interesting ring closure has been described in an attempt to effect an acylation of anisole with j3-phenylpropionic acid in the presence of chloroacetic anhydride.78 Only intramolecular acylation occurred, giving hydrindone-1 the yield after heating for forty-eight hours at 170° was 74%. 3,3-Diphenylhydrindone-l was similarly prepared in 67% yield. This further stresses the preference for intra- over inter-molecular acylation. 

The simplest synthesis of pseudothiohydantoins (8) is by condensation of thiourea (6) with substituted a-chloroacetates (7)3 5 [Eq. (1)]. Synthons6 of 7, epoxyacids,7 a-chloroacetic anhydrides,8 and dialkyl acetylenedi-carboxylate,9 have been successfully substituted for 7. Symmetrical diaryl-thioureas (9), conveniently synthesized from the corresponding arylamine and carbon disulfide, react with a-haloacetic acid derivatives to give a single thiazolidinone 108,10,11 [Eq. (2)]. 

Diethyl chloroaoetanllidomalonate, prepared by the reaction of amiidomalonic ester with chloroacetic anhydride or with the acid -in the presence of phosphorus trichloride, W ae treated with triethyl auiiuv in benxece solution at room temperature to give an 88% yield of... 

Cellulose esters of halogenated acids are exceptionally difficult to prepare. This is particularly true if the halogen is in the alpha position to the carboxyl group. Chloroacetic anhydride in the presence of acid catalysts esterifies cellulose only after severe degradation. The use of pyridine is prohibited because of side reactions with the reagent. Mixed... 

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