4-Chlorophenyl isocyanate

Chemical properties

white to yellow crystalline solid

The Uses of 4-Chlorophenyl isocyanate

4-Chlorophenyl isocyanate is used in the preparation of isothiocyanates. Aryl isocyanates undergo [2+2] cycloaddition reactions with dihydrofuran to give bicyclic ?-lactams in high yield.

The Uses of 4-Chlorophenyl isocyanate

4-Chlorophenyl isocyanate was used in the preparation of isothiocyanates.

Synthesis Reference(s)

The Journal of Organic Chemistry, 34, p. 3200, 1969 DOI: 10.1021/jo01262a089

General Description

Colorless to yellow liquid or crystals. Used as an intermediate in pesticide and pharmaceutical manufacture.

Reactivity Profile

Isocyanates and thioisocyanates are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].

Safety Profile

Poison by ingestion and inhalation. Unspecified human systemic effects. A severe eye and moderate skin irritant. A flammable liquid when exposed to heat or flame. Dangerous, can explode on distillation. When heated to decomposition it emits toxic fumes of Cl-, CN-, and NOx.

Purification Methods

Purify the isocyanate by recrystallisation from pet ether (b 30-40o) or better by fractional distillation. TOXIC irritant. [Beilstein 12 H 616, 12 III 1376, 12 IV 1213.]