2-Nitrochlorobenzene

Chemical properties

yellow solid with a characteristic odour

The Uses of 2-Nitrochlorobenzene

Intermediate, especially for dyes.

The Uses of 2-Nitrochlorobenzene

Chemical intermediate in manufacture of dyes, picric acid, lumber preservatives, and diaminophenol hydrochloride (a photographic developer)

The Uses of 2-Nitrochlorobenzene

1-Chloro-2-nitrobenzene was used in the synthesis of 1-hydroxybenzotriazole derivatives. It is important as a precursor to other compounds due to the two reactive sites present on the molecule.

Definition

ChEBI: 1-chloro-2-nitrobenzene is a C-nitro compound that is nitrobenzene in which one of the ortho- hydrogens has been replaced by chlorine. It is a C-nitro compound and a member of monochlorobenzenes.

Production Methods

Nitration of chlorobenzene with mixed acid (30/56/14) typically gives an isomer mix in 98 % yield consisting of 34 – 36 % 2-Nitrochlorobenzene, 63 – 65 % 4- chloronitrobenzene, and only ca. 1 % 3- chloronitrobenzene. The ortho – para ratio of about 0.55 is in sharp contrast to the 1.6 obtained with nitrotoluene isomers. As with the nitration of toluene, much work has been done on isomer control so that the producer might have some flexibility towards the balance of isomer demand. Although no major change in ratio has been achieved, the situation is better for nitrochlorobenzene than nitrotoluenes, because the favored isomer is in much greater demand. In further contrast to the nitration of toluene, the nitration of chlorobenzene in the presence of phosphoric acid decreases the proportion of 4-Nitrochlorobenzene, and the use of phosphoric acid in the presence of a transition-metal catalyst is said to increase the ortho – para ratio to ca. 0.8.

General Description

Yellow crystals with an aromatic odor. Sinks in water.

Air & Water Reactions

2-Nitrochlorobenzene may be sensitive to prolonged exposure to air and light. Insoluble in water.

Reactivity Profile

O-NITROCHLOROBENZENE is incompatible with strong bases and strong oxidizing agents. 2-Nitrochlorobenzene will react with ammonia.

Hazard

Toxic by inhalation and ingestion. Combustible. Questionable carcinogen.

Health Hazard

INHALATION: Headache, languour, anemia. Irritation of nose and throat, cyanosis, shallow respiration, convulsions, and coma. EYES: Irritation. SKIN: Irritation. INGESTION: Forms methemoglobin giving rise to cyanosis and blood changes.

Flammability and Explosibility

Not classified

Safety Profile

Suspected carcinogen with experimental carcinogenic and neoplastigenic data. Poison by ingestion, skin contact, and probably inhalation. Combustible when exposed to heat or flame. To fight fire, use water, foam. Potentially explosive reaction with ammonia at 160℃/30 bar. When heated to decomposition it emits toxic fumes of Cl-, NOx, and phosgene. See also other chloronitrobenzene entries and NITRO COMPOUNDS of AROMATIC HYDROCARBONS.

Purification Methods

Crystallise it from EtOH, MeOH or pentane (charcoal). [Beilstein 5 IV 721.]