Patent GB-1479040-A (GB)
Title: Aromatic amines their preparation and use as hardeners for epoxy resins
IPC: C08L63/00
Filed: 1974-08-23
Abstract: 1479040 Amines INSTITUT FRANCAIS DU PETROLE 23 Aug 1974 [29 Aug 1973] 37175/74 Heading C2C [Also in Division C3] The invention comprises aromatic amines of the formula NH 2 .Ar.COOR<SP>1</SP>O(CO.Ar<SP>1</SP>COOR<SP>1</SP>O) n CO.Ar.NH 2  in which each of the radicals Ar and Ar<SP>1</SP> is a divalent carbocylic or heterocyclic aromatic radical having two valences on different carbon atoms and having either one aromatic ring or 2 to 6 aromatic rings linked together, each two rings linked together being either fused, linked directly, or linked through a divalent radical selected from: -O-; -S-; -SO-; -SO 2 -; -CO-; -CHOR<SP>2</SP>-; -CF 2 -; -NR<SP>2</SP>-; -COO-; > CR<SP>2</SP>R<SP>3</SP> ; >SiR<SP>2</SP>R<SP>3</SP>; and -CO.NR2-; in which R<SP>2</SP> and R<SP>3</SP> are hydrogens or monovalent hydrocarbon radicals; and each radical R<SP>1</SP> is a divalent saturated straight or branched chain alkyl, cycloalkyl, alkylcycloalkyl or aralkyl radical having from 2 to 24 carbon atoms, or a divalent radical of the formula -(R<SP>4</SP>O) m R<SP>4</SP>-, in which R<SP>4</SP> is a divalent saturated aliphatic radical having from 2 to 10 carbon atoms, m is an integer from 1 to 100; n being an integer from 1 to 10. The compounds may be prepared by (a) reacting at least one aromatic dicarboxylic compound of the formula R<SP>1</SP>CO.Ar<SP>1</SP>.COR<SP>1</SP> (2), in which R<SP>1</SP> is -OH, -Cl, -Br, or a lower alkoxy radical, under esterification or transesterification conditions, with such an excess of at least one diol of the formula HOR<SP>1</SP>OH (3) as to form thereby an oligoester of the formula: HOR<SP>1</SP>O(CO.Ar<SP>1</SP>.COOR<SP>1</SP>O) n H, (4); (b) reacting the oligoester obtained by step (a), under esterification or transesterification conditions, with a molar amount corresponding substantially to the number of free hydroxy equivalents of said oligoester of at least one nitroaromatic carboxylic compound of the formula: N0 2 .Ar.C0R<SP>11</SP> in which R<SP>11</SP> is -OH, -Cl, -Br, or a lower alkoxy, cycloalkoxy or aryloxy radical, to form a nitrated oligoester of the formula and (c) hydrogenating the nitrated oligoester obtained by step (b), to form the desired amine In a modification the oligoester obtained by step (a) instead of being subjected to step (b) thereof, is acylated with an acid anhydride of at least one monocarboxylic aliphatic acid to form the corresponding ester, and the ester so obtained is reacted under transacidolysis conditions with a molar amount corresponding substantially to the number of equivalents of said acylate present in said ester, of at least one nitrocarboxylic aromatic compound of the general formula: N0 2 .Ar.C0R<SP>11</SP>, in which R<SP>11</SP> is -OH or a lower alkoxy radical, thereby forming a nitrated oligoester; and subsequently hydrogenating the nitrated oligoester as in step (c) above. In a further modification the oligoester obtained by step (a) is reacted under esterification or transesterification conditions, with a molar amount substantially corresponding to the number of free hydroxy equivalents of said oligoester of at least one aromatic aminocarboxy compound of the formula in which R<SP>11</SP> is -OH or a lower alkoxy radical, to form the desired amine.