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In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group (−NO 2) into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters ( −ONO 2 ) between alcohols and nitric acid (as occurs in the synthesis of nitroglycerin ).
The nitration product produced on the largest scale, by far, is nitrobenzene. Many explosives are produced by nitration including trinitrophenol (picric acid), trinitrotoluene (TNT), and trinitroresorcinol (styphnic acid). [3] Another but more specialized method for making aryl–NO 2 group starts from halogenated phenols, is the Zinke nitration.
Although discussions of directing groups usually focus on electronic effects (e.g. EWG vs EDGs), steric effect can prove influential. Thus, nitration of toluene gives approximately 2:1 ortho vs para-nitrotoluene. In the case of tert-butylbenzene, however, the selectivity is reversed:73% of the product is 4-nitro-tert-butybenzene]]. [4]
The methyl group in toluene is small and will lead the ortho product being the major product. On the other hand, the t-butyl group is very bulky (there are 3 methyl groups attached to a single carbon) and will lead the para product as the major one. Even with toluene, the product is not 2:1 but having a slightly less ortho product.
4-Nitrophenol is a product of the enzymatic cleavage of several synthetic substrates such as 4-nitrophenyl phosphate (used as a substrate for alkaline phosphatase), 4-nitrophenyl acetate (for carbonic anhydrase), 4-nitrophenyl-β-D-glucopyranoside and other sugar derivatives which are used to assay various glycosidase enzymes.
Synthesis of DNP (right) from phenol and nitric acid via 2-Nitrophenol and 4-Nitrophenol. DNP has the chemical formula HOC 6 H 3 (NO 2) 2. As a solid, it is a yellow, crystalline and has a sweet, musty odor. [1] [2] It sublimates, is volatile with steam, and is soluble in most organic solvents as well as aqueous alkaline solutions. [2]
At the time, phenol was obtained from coal as a co-product of coke ovens and the manufacture of gas for gas lighting. Laclede Gas reports being asked to expand production of phenol (and toluene) to assist the war effort. [16] Both Monsanto [17] and Dow Chemical [18] began manufacturing synthetic phenol in 1915, with Dow being the main producer ...
The simplest is phenol, C 6 H 5 OH. Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule. Phenol – the simplest of the phenols Chemical structure of salicylic acid, the active metabolite of aspirin. Phenols are both synthesized industrially and produced by plants and ...