92952-83-5Relevant academic research and scientific papers
3-nitro-4-hydroxy-propyl-aminophenol method for the preparation of
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Paragraph 0028; 0029; 0030, (2017/03/14)
The invention relates to a preparation method of 3-nitro-4-hydroxypropyl aminophenol. The method comprises the following steps: (1) carrying out a condensation reaction on 3-nitro-4-aminophenol and propyl chlorocarbonate under the action of calcium carbonate by taking 80% to 90% dioxane aqueous solution as a solvent; (2) dropwise adding alkali liquor with the mass concentration being 40% to 55% and carrying out a hydrolysis reaction by controlling a dropwise adding temperature within 50 DEG C to 55 DEG C, then reacting at 58 DEG C to 65 DEG C for 0.5 to 5 hours in a heat preservation manner, cooling to 30 DEG C to 40 DEG C, regulating pH to reach 5.5 to 6.5 and removing ethyl alcohol by evaporating so as to obtain a crude product of the 3-nitro-4-hydroxypropyl aminophenol; and (3) pulping the crude product of the 3-nitro-4-hydroxypropyl aminophenol in an n-propyl alcohol aqueous solution with the mass concentration being 18% to 22% so as to obtain the 3-nitro-4-hydroxypropyl aminophenol. According to the method, the total yield of the 3-nitro-4-hydroxypropyl aminophenol can reach above 90%, and the reactions in the two steps can be carried out in a manner of one-pot synthesis, so that the method has the advantages of being simple in production operation, fewer in byproducts, high in 3-nitro-4-hydroxypropyl aminophenol quality, less in pollution, low requirement on equipment and the like.
Substituted 4-amino-3-nitrophenols, processes for their preparation and hair-coloring agents containing these compounds
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, (2008/06/13)
The invention relates to new 3-nitro-4-aminophenols of the formula (I) STR1 in which R denotes hydrogen or halogen, preferably chlorine or bromine, and R' denotes hydrogen or alkyl, hydroxyalkyl, dihydroxyalkyl or halogenohydroxyalkyl which has 1 to 6 car
