Naphthalenetetracarboxylic acid derivatives and their use as semiconductors

A process for preparing compounds of the formula (I.a)

• in which
• at least one of the R1, R2, R3 and R4 radicals is a substituent which is selected from Br, F and CN, and the remaining radicals are each hydrogen,
• comprising:
• i) subjecting naphthalene-1,8;4,5-tetracarboxylic dianhydride to a bromination with N,N′-dibromoisocyanuric acid in the presence of more than 20% oleum to obtain 2,3,6,7-tetrabromonaphthalene-1,8;4,5-tetracarboxylic dianhydride
• ii) optionally, subjecting the 2,3,6,7-tetrabromonaphthalene-1,8;4,5-tetracarboxylic dianhydride to a substitution of the bromine atoms by fluorine or by cyano groups, or subjecting the 2,3,6,7-tetrabromonaphthalene-1,8;4,5-tetracarboxylic dianhydride to a partial substitution of the bromine atoms by hydrogen and, optionally, by fluorine or by cyano groups, and
• iii) optionally, subjecting the compounds obtained in step ii) to at least one separation and/or purification step.

A process for preparing compounds of the following formula

• in which
• at least one of the R1, R2, R3 and R4 radicals is a substituent which is selected from Br, F and CN, and the remaining radicals are each hydrogen,
• Z1, Z2, Z3 and Z4 are each O,
• Ra and Rb are each independently hydrogen or unsubstituted or substituted alkyl, alkenyl, alkadienyl, alkynyl, cycloalkyl, bicycloalkyl, cycloalkenyl, heterocycloalkyl, aryl or heteroaryl,
• or
• one of the Z1 or Z2 radicals is NRc, and Ra and Rc together are a bridging group having 2 to 5 atoms between the flanking bonds, and/or one of the Z3 or Z4 radicals is NRd, and Rb and Rd together are a bridging group having from 2 to 5 atoms between the flanking bonds,
• comprising:
• a1) subjecting naphthalene-1,8;4,5-tetracarboxylic dianhydride to a bromination with N,N′-dibromoisocyanuric acid to obtain a compound of the general formula I.a
• in which two or three or four of the R1, R2, R3 and R4 radicals are each Br, and the remaining radicals are each hydrogen,
• b1) subjecting the compound of the formula I.a obtained in step a1) to a substitution of the bromine by fluorine or cyano groups, and optionally, partly by hydrogen, and
• c1) subjecting the compound obtained in step b1) to a reaction with an amine of the formula Ra—NH2 and, optionally, an amine of the formula Rb—NH2,
• or
• subjecting the compound obtained in step b1) to a reaction with an amine of the formula H2N—X—NH2, where X is a divalent bridging group having from 2 to 5 atoms between the flanking bonds.