摘要:
4-Halo-1-naphthol is reacted with a secondary amine and formaldehyde to produce a reaction mixture containing a Mannich base which is hydrogenated to produce 2-methyl-1-naphthol. Advantageously, the procedure can be carried out in one pot.
摘要:
Anthraquinone compounds of formula I ##STR1## wherein R.sub.1 and R.sub.2 are methyl and R.sub.3 is propyl, or R.sub.1 and R.sub.2 are ethyl and R.sub.3 is methyl and A.sup.- is a cosmetically acceptable anion, are useful for the dyeing of hair. Compounds of formula I may advantageously be employed with direct dyes. Compositions and a method of use employing same are disclosed.
摘要:
Anthraquinone compounds of formula I ##STR1## wherein R.sub.1 and R.sub.2 are methyl and R.sub.3 is propyl, or R.sub.1 and R.sub.2 are ethyl and R.sub.3 is methyl and A is a cosmetically acceptable anion, are combined neutral, with semipermanent direct dyes in hair dyeing compositions.
摘要:
A one pot process is provided in which a Mannich base of the formula 5 is reacted with acetic anhydride to produce a diacetate derivative. Without any intermediate isolation, the derivative is hydrogenated to produce a reaction mixture containing 1-acetoxy-2-methylnaphthalene which is readily precipitated from the reaction mixture by addition of water. ##STR1##
摘要:
A method of producing and isolating 5,6-diacetoxyindole (DAI) in a single reaction vessel comprising the following steps:(a) preparing a first solution comprising dopa, water and a solubilizing agent selected from the group consisting of an acid having a pk.sub.a value equal to or less than 4 and a first base having a pk.sub.b value equal to or greater than 10;(b) preparing a second solution comprising an oxidant, a buffer and water;(c) mixing the first and second solutions to form a combined solution which is rendered oxygen-free and has a pH of from about 6 to about 9;(d) stirring the combined solution in an inert atmosphere until 5,6-dihydroxyindole (DHI) is substantially completely formed;(e) adding a derivatizing agent and a second base to the combined solution to form a final solution;(f) stirring the final solution until the DHI is substantially fully consumed;(g) cooling the final solution to precipitate DAI;(h) isolating the precipitated DAI.