Chloroacetic anhydride

Chemical Properties

brownish semi-transparent crystals, chunks or low

Uses

Chloroacetic anhydride has been used in the synthesis of 3,3-bis(sulfonato)-4,4-bis(chloroacetamido)azobenzene (BSBCA), a water-soluble, thiol-reactive and photo-switchable cross-linker, D,L-7-azatryptophan, 2-methyl-[3,4-di-O-acetyl-6-O-(chloroacetyl)-1,2-dideoxy-α-D-glucopyrano]-[2,1:4,5]-2-oxazoline.

Uses

In N-acetylation of amino acids in alkaline solution; preparation of cellulose chloroacetates.

Preparation

chloroacetic anhydride Synthesis: Powdered s odium monochloroacetate(113.3g, 1.138 mol) was added slowly for a period of 15 min at room temperature (which slowly raises to 60°C) to a stirred solution of commercially available chloroaceyl chloride (127.5g, 1mol) in dry benzene (136mL) was refluxed for 9h. Salts were filtered off, the filtrate was cooled to room temperature, diluted with n-hexane and further cooled to 0°C. The solid separated was then filtered, washed with dry hexane and dried to yield chloroacetic anhydride as white crystalline compound in 60% yield (80g); mp=46-49°C [Lit. mp=46°C]. Alternatively, the benzene layer was directly subjected to high vacuum distillation.The product collected at 109-10°C at 10mm vacuum on cooling chloroacetic anhydride in lump form in 70 % yield (93g). It was observed that, the latter method gives anhydride in lump form while the former method gives in crystalline form.

Purification Methods

Crystallise the it from *benzene. [Eglinton et al. J Chem Soc 1860 1954, Beilstein 2 IV 487.]