DNP

Interaction of formaldehyde with 2,4-dinitrophenylhydrazine in acid media causes 2,4-dinitrophenylhydrazone (DNPhydrazone) formaldehyde formation. Gas-chromatographic analysis of 2,4-DNP-hydrazone formaldehyde toluene extract with an electron holding detector makes it possible to detect it at the level of 0,001 mg/dm. Phenol is detected in the form of tribromphenol yield, the hexane extract of which undergoes chromatography with an electron holding detector which provides the level of phenol detection of 0.001 mg/dm (the limit of quantitative detection). 

In a synthesis of sativene a carbonyl group was protected as a 2,4-DNP while a double bond was hydrated with BH3/H202/0H . Attempted protection of the carbonyl group as a ketal caused migration of the double bond protection as an oxime or oxime acetate was unsatisfactory since they would be reduced with BH3. 

Imine formation from such reagents as hydroxylamine and 2,4-dinitro-phenylhydrazine is sometimes useful because the products of these reactions— oximes and 2,4-dinitrophenylhydrazones (2,4-DNPs), respectively—are often crystalline and easy to handle. Such crystalline derivatives are occasionally prepared as a means of purifying and characterizing liquid ketones or aldehydes. 

The ethanal was converted to its 2,4-DNP derivative, obtained in 87% yield.) It may also be noted that for this redox reaction, iridium retains the +3 state throughout. The more labile chloride trans to phosphine is replaced... 

Kesner, L., E. Mundtwyler, G. E. Griffin, and J. Abrams Automatic column chromatography of ether-soluble and water-soluble 2,4-DNP-derivatives of amino acids, peptides and amines. Analytic. Chem. 35, 83-89 (1963). 

Because the rate of the ETC increases, with no ATP synthesis, energy is released as heat. Important uncouplers include 2,4-dinitrophenol (2,4-DNP) and aspirin (and other salicylates). Brown adipose tissue contains a natural uncoupling protein (UCP, formerly called thernio-genin), which allows energy loss as heat to maintain a basal temperature around the kidneys, neck, breastplate, and scapulae in newborns. 

Synonyms AI3-01535 Aldifen BRN 1246142 Caswell No. 392 CCRIS 3102 Chemox PE Dinofan a-Dinitrophenol DNP 2,4-DNP EINECS 200-087-7 EPA pesticide chemical code 037509 Fenoxyl carbon N l-Hydroxy-2,4-dinitrobenzene Maroxol-50 Nitro kleenup NSC 1532 RCRA waste number P048 Solfo black B Solfo black BB Solfo black 2B supra Solfo black G Solfo black SB Tetrasulphur black PB Tetrosulphur PBR UN 1320 X 32. 

DNP-derivatives are yellow, orange or red solids, usejul for characterisation of aldehydes and ketones. 

Solution (A) forms 2,4-DNP derivative. Therefore, it is an aldehyde or a ketone. 

Synonyms 2,4-DNP Aldifen Chemox PE Dinofan Fenoxyl Carbon N Maroxol 50 Caswell No. 392 Sulfo Black B Nitro Kleenup... 

Toxicology. 2,4-Dinitrophenol (2,4-DNP) uncouples oxidative phosphorylation from electron transport, resulting in diminished production of ATP, with the energy dissipated as heat, which can lead to fatal hyperthermia. ... 

Fatal cases of 2,4-DNP poisoning were reported among workers in the munitions industry in France. Workers were exposed to airborne vapor and dust of 2,4-DNP and had direct dermal contact with the solid material, although duration and levels of exposure were not reported. Deaths were preceded by sudden onset of extreme fatigue, elevation of body temperature to 40°C or more, profuse sweating, thirst, and labored respiration. No characteristic lesions were found at autopsy. 

DNP in a US chemical plant for a few months developed fever, profuse sweating, and restlessness. After treatment and rest they returned to work, collapsed, and died. Workroom air levels, measured after the deaths, were found to be at least 40mg/m , and significant dermal exposure may also have occurred. 

During the 1930s, 2,4-DNP was used extensively as a weight loss agent. Cataracts developed in a small percentage of patients who took the agent, with at least 164 cases in the published literature. Representative case reports that provided doses indicate that cataracts developed in the patients at doses... 

DNP induced cataractogenesis appears to vary widely. Development of agranulocytosis, peripheral neuritis, and dermal effects such as rash, pruritus, urticaria, and maculopapular skin lesions were also observed. ... 

An ACGIH threshold limit value (TLV) has not been established for 2,4-DNP. 

The pKa of 2,4-DNP is 3.94 (Schwarzenbach et al., 1988). Thus, at pH = 7.5, more than 99.99% of the chemical is present in its anionic form, and sorption can be neglected. When further assuming that 2,4-DNP does not undergo any transformation, the compound can be assumed to exhibit a conservative behavior in the aquifer. 

---