As a bifunctional compound, trichloroacetonitrile can react at both the trichloromethyl and the nitrile group. The electron withdrawing effect of the trichloromethyl group activates the nitrile group for nucleophilic additions. The high reactivity makes trichloroacetonitrile a versatile reagent, but also causes its susceptibility towards hydrolysis. The production of trichloroacetonitrile by dehydration of trichloroacetamide was first described in 1873 by L. Bisschopinck at the Katholieke Universiteit Leuven. Trichloroacetonitrile can be obtained by chlorination of acetonitrile on a Zn, Cu and alkaline earth metal halides impregnated activated carbon catalyst at 200-400 °C in 54% yield. The high temperatures required by this process favours the formation of by-products, such as tetrachloromethane. In contrast, the chlorination of acetonitrile saturated with hydrogen chloride leads to pure trichloroacetonitrile even at 50-80 °C in good yields. Like other halogenated acetonitriles, trichloroacetonitrile is produced from organic substances such as algae, humic acids and proteinaceous material in the disinfecting chlorination of water from natural sources. Freshly distilled trichloroacetonitrile is a colorless, liquid with a pungent odor that discolours rapidly yellowish to light brown. It is sensitive towards water, acids and bases. The bond lengths are 146.0 pm (C-C), 116.5 pm (C-N) and 176.3 pm (C-Cl). The bond angle is 110.0 ° (ClCCl). The substitution of all electronegative substituents in trichloroacetonitrile by nucleophilic attack of alkoxide anions produces orthocarbonic acid esters in high yield. Due to the high reactivity of the chlorine atoms, trichloroacetonitrile can be used (especially in combination with triphenylphosphine) to convert allylic alcohols into the corresponding allylic chlorides. With carboxylic acids, acyl chlorides are obtained. Due to the mild reaction conditions, the Cl3CCN/PPh3 system is also suitable for the activation of carboxylic acids and their linkage with supported amino compounds to amides (peptides) in solid-phase syntheses.