Orthonitrobenzene

Orthonitrobenzene, also known as 1-nitro-2-benzene, is an organic compound with the chemical formula C6H5NO2. It is one of three isomers of nitrobenzene, the others being metanitrobenzene and paranitrobenzene. At room temperature, orthonitrobenzene is a yellow crystalline solid. It has a characteristic odor.

The compound is synthesized through the nitration of benzene, typically using a mixture of nitric acid and sulfuric acid. The reaction conditions can influence the distribution of isomers, with specific temperatures and reagent concentrations favoring the ortho isomer. Orthonitrobenzene is sparingly soluble in water but is soluble in many organic solvents such as ethanol and ether.

Industrially, orthonitrobenzene serves as an intermediate in the production of various chemicals. It is primarily used in the synthesis of ortho-anisidine and ortho-phenetidine, which are employed in the manufacture of dyes and pharmaceuticals. It can also be reduced to ortho-nitroaniline, another important chemical intermediate. Due to its nitro group, orthonitrobenzene is a relatively reactive compound and can undergo various chemical transformations.