You have nitrated para-bromotoluene. Since this compound has two ortho/para directing groups in a conflicting orientation (para to each other), a mixture of products will result (formulas shown to the right). The chief product is 4-bromo-2-nitrotoluene (left formula). Proceeding to the desired product from this compound is not feasible, since the location of the nitro substituent relative to the methyl group (destined to become the carboxyl group) is ortho not meta, as desired.

Could the minor product, 4-bromo-3-nitrotoluene, be converted to the target molecule?