2Nitrochlorobenzene

2-Nitrochlorobenzene, also known as ortho-nitrochlorobenzene or ONCB, is an organic compound with the chemical formula C6H4ClNO2. It is one of three isomers of nitrochlorobenzene, the others being 3-nitrochlorobenzene and 4-nitrochlorobenzene. At room temperature, 2-nitrochlorobenzene is a yellow crystalline solid. It has a distinct, somewhat pungent odor.

The compound is typically produced by the nitration of chlorobenzene. This process involves reacting chlorobenzene with a mixture of nitric acid and sulfuric acid. The reaction yields a mixture of the three isomers, which are then separated through distillation or crystallization.

2-Nitrochlorobenzene is primarily used as an intermediate in the synthesis of other chemicals. It is a precursor for the production of ortho-nitroaniline and ortho-chloroaniline, which are used in the manufacturing of dyes, pigments, and pharmaceuticals. It also finds applications in the synthesis of rubber chemicals and agrochemicals.

Due to its chemical properties, 2-nitrochlorobenzene is considered a hazardous substance. It can be irritating to the skin, eyes, and respiratory system. Ingestion or prolonged exposure can lead to more severe health effects, including methemoglobinemia, a condition where the blood's ability to carry oxygen is reduced. Proper handling procedures and personal protective equipment are therefore essential when working with this compound. It is also important to note its potential environmental impact and to dispose of it responsibly.