Telescoping syntheses of 2-methoxymethyl-p-phenylenediamine
The invention relates to processes for preparing 2-methoxymethyl-p-phenylenediamine (I), cosmetically acceptable salts thereof, or mixtures thereof.
1. A process for preparing 2-methoxymethyl-p-phenylene diamine (I), a cosmetically acceptable salt thereof, or mixture thereof, the process comprising the steps of:
(a1) (a1) alkylating 1,4-benzoquinone (VIII) in the presence of 2-methoxyacetic acid (IX) to form a mixture of 2-methoxymethyl-1-4-benzochinone (IV) and 1,4-benzoquinone (VIII);
(b1) condensing 2-methoxymethyl-1-4-benzochinone (IV) and 1,4-benzoquinone (VIII) with NH 2 R1 to form a mixture of 2-(methoxymethyl)-N1(R1), N4(R1)-cyclohexa-2,5-diene-1,4-diimine (Va) and N1(R1), N4(R1)-cyclohexa-2,5-diene-1,4-diiminine (Xa) wherein moiety R1 of NH 2 R1 is selected from OH, NH2, linear or branched (C1-C6)alkyl which optionally may be substituted with OH, linear or branched (C1-C6)alkylene-(C5-C6) cycloalkyl and linear or branched (C1-C6)alkyl benzol;
(b2) in the mixture obtained in step (b1), oxidizing 2-(methoxymethyl)-N1(R1), N4(R1)-cyclohexa-2,5-diene-1,4-diimine (Va) and N1(R1), N4(R1)-cyclohexa-2,5-diene-1,4-diiminine (Xa); to form a mixture of 2-(methoxymethyl)-1,4-dinitroso-benzene (XII) and 1,4-dinitrosobenzene (XIII);
(b3) isolating 2-(methoxymethyl)-1,4-dinitroso-benzene (XII) and 1,4-dinitrosobenzene (XIII);
(c1) reacting 2-(methoxymethyl)-1,4-dinitroso-benzene (XII) in the presence of a hydrogen source to form 2-methoxymethyl-P-phenylene diamine (I) and
(c2) reacting 1,4-dinitroso-benzene (XIII) in the presence of a hydrogen source to form p-phenylene diamine(XI).
2. The process of claim 1 wherein step (b1) comprises condensing 2-methoxymethyl-1,4 benzochinone (IV) and 1,4)-benzoquinone (VIII) with hydroxyamine NH2OH to form a mixture of bis-oxime 1-(methoxymethyl)-cyclohexa-2,5-diene-1,4-dione oxime (Vb) and cyclohexa-2,5-diene-1,4-dione oxime (Xb), and wherein step (b2) comprises reacting a mixture of (Vb) and (Xb) to form a mixture of (XII) and XIII).
3. The process of claim 1 , wherein step (ci) and/or step (c2) is carried out in the presence of a catalyst selected from the group consisting of Fe, Pd/C, Pd(OH) 2 , Raney-Ni, Pt/C, PtO 2 and mixtures thereof.
4. The process of claim 1 wherein the isolation of 2-(methoxymethyl)-1,4-dinitroso-benzene (XII) and 1,4-dinitrosobenzene (XIII) in step (b3) separates 2-(methoxymethyl)-1,4-dinitroso-benzene (XII) from 1,4-dinitrosobenzene (XIII).