Telescoping synthesis of 2-methoxymethyl-p-phenylenediamine

Abstract

A telescoping process for the preparation of 2-methoxymethyl-p-phenylenediamine, a cosmetically acceptable salt thereof, or mixture thereof. The process according to the present invention is a particularly cost effective process in that it avoids sophisticated chemical steps which requires special equipment or expensive catalysts and in that it comprises a recycling step of one of the starting materials, namely 2-methoxymethylaniline.

Description

[0001] field of invention [0002] The present invention relates to a novel telescoping synthesis of 2-methoxymethyl-p-phenylenediamine or salts thereof according to formula (I). This compound is known in the industry as a hypoallergenic primary dye precursor for use in oxidative hair dye compositions as an alternative to traditional p-phenylenediamine or p-toluenediamine dye precursors. [0003] [0004] Background of the invention [0005] p-Phenylenediamine derivatives are important precursors for oxidative hair coloring. They are often used to create dark shades. P-phenylenediamine derivatives have been used for decades in hair coloring. Among the p-phenylenediamine derivatives, a particularly favorable candidate, namely 2-methoxymethyl-p-phenylenediamine, has been identified. Such dye precursors are particularly advantageous because they are typically characterized by a lower sensitization potential than conventional p-phenylenediamine or p-toluenediamine dye precurs...

AI Technical Summary

Problems solved by technology

However, this synthetic route is unsatisfactory in terms of purity results and also produces some by-products such as aminobiphenyl

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