Chloroacetic

Chloroacetic refers to a group of chlorinated derivatives of acetic acid, typically the chloroacetic acids. The most common are monochloroacetic acid (MCAA, ClCH2COOH), dichloroacetic acid (DCAA, Cl2CHCOOH), and trichloroacetic acid (TCAA, Cl3CCOOH). These compounds are constitutional isomers of chlorinated acetic acid and share general properties such as relatively high acidity, water solubility, and corrosivity. Their pKa values decrease as more chlorine atoms are substituted on the methyl group: MCAA around 2.8, DCAA around 1.3, and TCAA around 0.7.

Chloroacetic acids are typically crystalline solids at room temperature and are highly soluble in water. They are strong carboxylic acids for their class and can be corrosive to skin and mucous membranes. They may release hydrochloric acid upon hydrolysis or reaction with bases. Because of their reactivity and toxicity, these compounds are handled under controlled conditions with appropriate protective equipment and ventilation, and they are subject to strict regulatory controls in many jurisdictions.

Production of monochloroacetic acid is primarily by chlorination of acetic acid in the presence of catalysts, often with subsequent purification steps. Alternative routes include chlorination of chloroacetyl derivatives or hydrolysis of chlorinated acyl chlorides. Dichloro- and trichloroacetic acids can be prepared by further chlorination of the monochloro derivative or via direct chlorination of suitable precursors.

Uses of chloroacetic acids are industrial and synthetic: they serve as intermediates in the manufacture of various chemicals, including salts used in the production of carboxymethyl cellulose derivatives, polymers, surfactants, and some agrochemicals. They are also employed in organic synthesis for introducing the chloroacetyl motif into compounds. Safety and environmental considerations are essential due to their corrosivity and potential toxicity.