Chemical Properties
yellow or bright yellow needle-like crystals. It can volatilize with water vapor and has the fragrance of benzaldehyde. Soluble in ethanol, ether, benzene, slightly soluble in water, flash point>110℃, reacts violently with pyrrole.
Uses
2-Nitrobenzaldehyde is a benzaldhyde with a nitro group substituted in the ortho position. 2-Nitrobenzaldehyde is used in the preparation of dyes and colorants such as Indigo carmine. 2-Nitrobenzaldehyde gas been shown to be a useful photoremovable protecting group as well as in the preparation of more effective ones such as o-Nitrophenylethylene glycol.
Definition
ChEBI: 2-nitrobenzaldehyde is benzaldehyde substituted at the ortho-position with a nitro group. It is a C-nitro compound and a member of benzaldehydes.
Application
2-Nitrobenzaldehyde can react with chitosan to form 2-nitrobenzyl-chitosan, which is soluble in trifluoroacetic acid and can also be electrospun into nanofiber matrices. On photolysis, the nitrobenzyl group is cleaved to form neat chitosan nanofiber matrices. The same principle has been applied for the preparation of gelatin nanofiber matrices. The condensation of o-NBA with 2-aminobenzothiazole forms o-nitrobenzylidene 2-aminobenzothiazole, a Schiff′s base that can react with metal ions to form complexes.
General Description
The 2-Nitrobenzyl group of 2-nitrobenzaldehyde is photolabile that can be cleaved when exposed to UV-light.
Synthesis
50 g (0.24 mol) of 2-nitrophenylpyruvic acid of melting point 115° C are introduced into 500 ml of aqueous sodium carbonate until a clear solution is obtained. After the addition of 350 ml of toluene, the mixture is cooled to 0° C, and 40 g of solid potassium permanganate is then added in portions at 0°- 3° C. After one hour at 0°- 3° C, 95 ml of 50% strength sulphuric acid are added dropwise. The temperature is not allowed to rise above 30° C. The reaction mixture is filtered, and the toluene phase is separated from the filtrate. The filter residue is washed with toluene, and the combined toluene phases are extracted with 15% strength sodium carbonate solution and with water. The toluene phase is then dried with sodium sulfate and concentrated in a vacuo. The remaining residue consists of 19.7 g (54.7% of theory) of 2-nitrobenzaldehyde, which crystallizes on cooling.
Purification Methods
Crystallise the aldehyde from toluene (2-2.5mL/g) by addition of 7mL pet ether (b 40-60o) for 1mL of solution. It can also be distilled under reduced pressures. [Beilstein 7 IV 584.]
