| abstract |
A benzoic acid derivative and a dehydration-condensation agent, each of which is represented by formula (I) or (II). In formulae (I) and (II), R 1 represents a haloalkyl group, a halogen atom or a cyano group; and R 2 , R 3 and R 4 independently represent a hydrogen atom, a haloalkyl group, a halogen atom or a cyano group. In formula (I), two R 1 's, two R 2 's, two R 3 's or two R 4 's may be the same as or different from each other. |