A process for the preparation of a benzo-hetero[1,3]diazole compound disubstituted with brominated heteroaryl groups having general formula: wherein: - W represents an oxygen atom; a sulfur atom; an NR group wherein R represents a hydrogen atom, or a C 1 -C 20 alkyl group; - Y represents a sulfur atom; an oxygen atom; a selenium atom; an NR group wherein R represents a hydrogen atom, or a linear or branched C 1 -C 30 alkyl group; - Z represents a nitrogen atom; or a group CR 2 wherein R 2 represents a hydrogen atom, or a linear or branched C 1 -C 20 alkyl group; - R 1 represents a hydrogen atom; a linear or branched C 1 -C 20 alkyl group; a cycloalkyl group optionally substituted; an aryl group optionally substituted; a linear or branched C 1 -C 20 alkoxyl group; a polyethyleneoxyl group R-O-[-CH 2 -CH 2 -O] n - wherein R has the same meaning defined above and n is an integer ranging from 1 to 4; a group -R'-OH wherein R' represents a linear or branched C 1 -C 20 alkylene group; a group -R'-OR" wherein R' has the same meanings defined above and R" represents a linear or branched C 1 -C 20 alkyl group, or a polyethyleneoxyl group R-O-[-CH 2 -CH 2 -O] n - wherein R has the same meaning defined above and n is an integer ranging from 1 to 4; a group -COR wherein R has the same meanings defined above; a group -COOR wherein R has the same meanings defined above; a group -CHO; a cyano group (-CN); - or R 1 and R 2 can be optionally bound to each other so as to form, together with the carbon atoms to which they are bound, a cycle or a polycyclic system containing from 3 to 14 carbon atoms, saturated, unsaturated, or aromatic, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorous, selenium; - R 3 and R 4, the same as each other, represent a hydrogen atom; a linear or branched C 1 -C 20 alkyl group; a linear or branched C 1 -C 20 alkoxyl group; a group -COOR wherein R has the same meanings defined above; a cyano group (-CN); - or R 3 and R 4 can be optionally bound to each other so as to form, together with the carbon atoms to which they are bound, a cycle or a polycyclic system containing from 3 to 14 carbon atoms, saturated, unsaturated, or aromatic, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorous, selenium; said process comprising reacting at least one dihalogenated benzohetero[1,3]diazole compound having general formula: wherein X represents a halogen atom selected from chlorine, bromine, preferably bromine; Y, R 3 and R 4 have the same meanings described above; with at least one brominated heteroaryl compound having general formula: wherein W, Z and R 1, have the same meanings described above. - W represents an oxygen atom; a sulfur atom; an NR group wherein R represents a hydrogen atom, or a C 1 -C 20 alkyl group; - Y represents a sulfur atom; an oxygen atom; a selenium atom; an NR group wherein R represents a hydrogen atom, or a linear or branched C 1 -C 30 alkyl group; - Z represents a nitrogen atom; or a group CR 2 wherein R 2 represents a hydrogen atom, or a linear or branched C 1 -C 20 alkyl group; - R 1 represents a hydrogen atom; a linear or branched C 1 -C 20 alkyl group; a cycloalkyl group optionally substituted; an aryl group optionally substituted; a linear or branched C 1 -C 20 alkoxyl group; a polyethyleneoxyl group R-O-[-CH 2 -CH 2 -O] n - wherein R has the same meaning defined above and n is an integer ranging from 1 to 4; a group -R'-OH wherein R' represents a linear or branched C 1 -C 20 alkylene group; a group -R'-OR" wherein R' has the same meanings defined above and R" represents a linear or branched C 1 -C 20 alkyl group, or a polyethyleneoxyl group R-O-[-CH 2 -CH 2 -O] n - wherein R has the same meaning defined above and n is an integer ranging from 1 to 4; a group -COR wherein R has the same meanings defined above; a group -COOR wherein R has the same meanings defined above; a group -CHO; a cyano group (-CN); - or R 1 and R 2 can be optionally bound to each other so as to form, together with the carbon atoms to which they are bound, a cycle or a polycyclic system containing from 3 to 14 carbon atoms, saturated, unsaturated, or aromatic, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorous, selenium; - R 3 and R 4, the same as each other, represent a hydrogen atom; a linear or branched C 1 -C 20 alkyl group; a linear or branched C 1 -C 20 alkoxyl group; a group -COOR wherein R has the same meanings defined above; a cyano group (-CN); - or R 3 and R 4 can be optionally bound to each other so as to form, together with the carbon atoms to which they are bound, a cycle or a polycyclic system containing from 3 to 14 carbon atoms, saturated, unsaturated, or aromatic, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorous, selenium; said process comprising reacting at least one dihalogenated benzohetero[1,3]diazole compound having general formula: wherein X represents a halogen atom selected from chlorine, bromine, preferably bromine; Y, R 3 and R 4 have the same meanings described above; with at least one brominated heteroaryl compound having general formula: wherein W, Z and R 1, have the same meanings described above.