88-63-1Relevant articles and documents
Method for preparing 2,4-diaminobenzenesulfonic acid
-
Paragraph 0049-0075, (2018/11/03)
The invention relates to a method for preparing 2,4-diaminobenzenesulfonic acid. The method comprises the following steps: (1) adding m-phenylenediamine and an organic solvent to a vessel equipped with a thermometer and a stirring device, and dissolving at room temperature; a feed ratio of m-phenylenediamine to the organic solvent is 1g to (5 to20mL); (2) slowly adding sulfur trioxide to the solution in (1) under stirring, and raising the temperature to 20 to 100 DEG C, and reacting for 2.5 swung dash 60h; wherein the molar ratio of m-phenylenediamine to sulfur trioxide is 1:(1.0-3.0); (3) filtering and drying the reaction solution in (2) to obtain 2,4-diaminobenzenesulfonate acid. The method for preparing 2,4-diaminobenzenesulfonic acid has the advantages of mild conditions, simple process, low cost, recyclability of organic reagents, no waste acid formation, high product purity and high yield and the like.
SUSTAINABLE CHEMICAL PROCESS FOR REDUCTION OF NITRO COMPOUNDS (R-NO2) OR NITROSO COMPOUNDS (R-NO) CONTAINING SULPHONIC OR CARBOXYLIC GROUP INTO CORRESPONDING AMINO COMPOUNDS (R-NH2) WITH INHERENT RECYCLE OF ALL ACIDIC STREAMS GENERATED IN SYNTHESIS
-
Page/Page column 32; 35, (2011/05/06)
The process of the present invention creates a sustainable and closed water loop allowing inherent recycles of all liquid streams generated in the process. The liquid streams generated during the process of the invention are inherently recycled completely, making the process of the present invention a zero liquid discharge process which is environmentally friendly and sustainable. This invention further relates to a sustainable chemical process of reduction of R- NO2 or R-NO into corresponding R-NH2 that produces environmentally friendly R-NH2 in good yields and selectivity with large of mother liquor recycle. The process has a wide scope in that it can be applied to a number of molecules.
One step hair coloring compositions using salts
-
, (2008/06/13)
A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.