2-nitrobenzaldehyde

2-Nitrobenzaldehyde

Names
Preferred IUPAC name 2-Nitrobenzaldehyde
Other names Nitrobenzaldehyde ortho-Nitrobenzaldehyde o-Nitrobenzaldehyde
Identifiers
CAS Number	552-89-6 Y
3D model (JSmol)	Interactive image
ChemSpider	10630 Y
ECHA InfoCard	100.008.206
PubChem CID	11101
InChI InChI=1S/C7H5NO3/c9-5-6-3-1-2-4-7(6)8(10)11/h1-5H Y Key: CMWKITSNTDAEDT-UHFFFAOYSA-N Y InChI=1/C7H5NO3/c9-5-6-3-1-2-4-7(6)8(10)11/h1-5H Key: CMWKITSNTDAEDT-UHFFFAOYAD
SMILES O=[N+]([O-])c1ccccc1C=O
Properties
Chemical formula	C7H5NO3
Molar mass	151.12 g/mol
Appearance	Pale yellow crystalline powder
Melting point	43 °C (109 °F; 316 K)
Boiling point	152 °C (306 °F; 425 K)
Solubility in water	Insoluble
Magnetic susceptibility (χ)	-68.23·10−6 cm3/mol
Hazards
Main hazards	Harmful, Potentially mutagenic
R-phrases (outdated)	R36 R37 R38 R41
S-phrases (outdated)	S26 S28
NFPA 704	1 2 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

2-Nitrobenzaldehyde is an organic aromatic compound containing a nitro group ortho to formyl. 2-Nitrobenzaldehyde once was produced as an intermediate in the synthesis of the popular dye Indigo.

The main routes to nitrobenzaldehyde begin with the nitration of styrene and cinnamic acid followed by the conversions of the resulting 2-nitrostyrene and 2-nitrocinnamic acids. Cinnamaldehyde can also be nitrated, e.g., in a solution of acetic anhydride in acetic acid, in high-yield to 2-nitrocinnamaldehyde. This compound is then oxidized to 2-nitrocinnamic acid, which is decarboxylated to the 2-nitrostyrene. The vinyl group can be oxidized in a number of different ways to yield 2-nitrobenzaldehyde.

In one synthetic process, toluene is mono-nitrated at cold temperatures to 2-nitrotoluene, with about 58% being converted to the ortho- isomer, the remaining forming meta- and para- isomers. The 2-nitrotoluene can then be oxidized to yield 2-nitrobenzaldehyde.

Alternatively, 2-nitrotoluene as formed above can be halogenated to a 2-nitrobenzyl halide followed by oxidation with DMSO and sodium bicarbonate to yield 2-nitrobenzaldehyde, which is subsequently purified with the creation of a bisulfite adduct.

The nitration of benzaldehyde produces mostly 3-nitrobenzaldehyde, with yields being about 19% for the ortho-, 72% for the meta- and 9% for the para isomer. For this reason, the nitration of benzaldehyde to yield 2-nitrobenzaldehyde is not cost-effective.