Ortho-substituted benzoic acid derivatives

Ortho-substituted benzoic acid derivatives of the formula I, in which R1 is A, CF3, CH2F, CHF2, C2F5, CN, NO2, Hal, C=ch or -X-R4, R2 is CF3, -Son-R6 or -SO2NR4R5, R3 is CN, Hal, COA, CHO, CSNR7R8 or CONR7R8, Q is -N=C(NH2)2, C1, Br, OA, O-CO-A, O-CO-Ph, OH, or another reactive esterified OH group or a leaving group which can readily be substituted nucleophilically, R4 is H, A, cycloalkyl having from 5 to 7 C atoms, CF3, CH2F, CHF2, CH2CF3, Ph or -CH2-Ph, R5 is H or A, or else R4 and R5 are together also alkylene having from 4 to 5 C atoms, where one CH2 group can also be replaced by 0, S, NH, N-A or N-CH2-Ph, R6 is A or Ph, R7 and R8 are in each case, independently of one another, H, A or Ac, A is alkyl having from 1 to 6 C atoms, X is O, S or NR5, Ph is phenyl which is unsubstituted or is substi-tuted once, twice or three times by A, OA, NR4R5, F, Cl, Br, I or CF3, Ac is alkanoyl having from 1 to 10 C atoms, or aroyl having from 7 to 11 C atoms, and n is 1 or 2, and the pharmaceutically tolerated salts thereof, are suitable for use as valuable intermediates for the preparation of medicaments, in particular of inhibitors of the cellular Na/H antiporter.