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4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H 2 NC 6 H 4 OH. Typically available as a white powder, [ 3 ] it is commonly used as a developer for black-and-white film , marketed under the name Rodinal .
The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
The classical methods for the production of paracetamol involve the acetylation of 4-aminophenol with acetic anhydride as the last step. They differ in how 4-aminophenol is prepared. In one method, nitration of phenol with nitric acid affords 4-nitrophenol, which is reduced to 4-aminophenol by hydrogenation over Raney nickel.
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.
Phenol ethers, similarly to regular ethers, are less hydrophilic than its precursors, phenols and alcohols, both of which can donate and accept hydrogen bonds. Phenol ethers, however, are still able to accept hydrogen bonds through the ethereal oxygen, allowing for its slight solubility in polar solvents.
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry , alcohols and carboxylic acids contain one or more hydroxy groups.
A solution of 4-nitrophenol appears colorless below pH 5.4 and yellow above pH 7.5. [3] This color-changing property makes this compound useful as a pH indicator. The yellow color of the 4-nitrophenolate form (or 4-nitrophenoxide) is due to a maximum of absorbance at 405 nm (ε = 18.3 to 18.4 mM −1 cm −1 in strong alkali). [4]
4-Aminobiphenyl (4-ABP) is an organic compound with the formula C 6 H 5 C 6 H 4 NH 2. It is an amine derivative of biphenyl . It is a colorless solid, although aged samples can appear colored. 4-Aminobiphenyl was commonly used in the past as a rubber antioxidant and an intermediate for dyes. [ 5 ]