2,2′-diaminobiaryls having one primary and one secondary amine
Novel 2,2′-diaminobiaryls having one primary and one secondary amine and an electrochemical process for preparation thereof.
1. A process for preparing 2,2′-diaminobiaryls, comprising:
a2) reacting a compound of the formula (VIIa):
with X 12 to give (VIIb):
b2) reacting a compound of the formula (VIIIa):
with X 12′ to give (VIIIb):
c2) electrochemically coupling:
(VIIb) with (VIIIb) to give (IXa)
in a suitable electrolyte medium where the compound, (VIIb) or (VIIIb), having the higher oxidation potential is present in excess:
d2) selectively detaching X 12′ or X 12 , with conversion of (IXa) to (Xa) or (Xb):
where
R 11 , R 12 , R 13 , R 14 are selected from the group consisting of:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —O—(C 6 -C 20 )-aryl, —(C 6 -C 20 )-aryl, —S-alkyl, —S-aryl, halogen, —COO—(C 1 -C 12 )-alkyl, —CONH—(C 1 -C 12 )-alkyl, —CO—(C 1 -C 12 )-alkyl, —CO—(C 6 -C 20 )-aryl, —COOH, —OH, —SO 3 H, —CN, and —N[(C 1 -C 12 )-alkyl] 2 ;
R 15′ , R 16′ , R 17′ , R 18′ , R 19′ , R 20′ are selected from the group consisting of:
—H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —O—(C 6 -C 20 )-aryl, —(C 6 -C 20 )-aryl, —S-alkyl, —S-aryl, halogen, —COO—(C 1 -C 12 )-alkyl, —CONH—(C 1 -C 12 )-alkyl, —CO—(C 1 -C 12 )-alkyl, —CO—(C 6 -C 20 )-aryl, —COOH, —OH, —SO 3 H, and —N[(C 1 -C 12 )-alkyl] 2 ;
where the alkyl and aryl groups mentioned may be substituted;
X 12 and X 12′ are selected from the group consisting of:
tert-butyloxycarbonyl, methyloxycarbonyl, benzyloxycarbonyl, phenyloxycarbonyl, acetyl, trifluoroacetyl, benzoyl, and sulphonyl, sulphenyl;
and X 12 is not the same radical as X 12′ .