My book says:
If you react a sulfonic acid with PCl5 at high temperatures, it will become a halide. (yeah, right)
Hey, why don't you just make ethylene chlorohydrin and react it with an excess of ammonia, then HBr to give the desired 2-bromoethylamine? Note: antifreeze is much cheaper than taurine or PCl5.
I think the alkylation would work. No idea of yields.
You may wish to consider making 2,5-phenylmagnesium bromide grignard and reacting it with the above reagent as a substitute for F.C. alkylation.