Antoncho
I looked a bit but nothing poped out with the answer.
I did find this tho....
mmmm HCN
Why can't such pretty chemistry use benign reagents??
Preparation of 4-bromo-2,5-dimethoxybenzoic acid.
Bortnik, S. P.; Landau, M. A.; Siryachenko, B. V.; Dubov, S. S.; Yarovenko, N. N. USSR.
Zh. Org. Khim. (1972), 8(2), 340-1.
Journal written in Russian.
Abstract
2,5-(MeO)2C6H3Br reacted with anhyd. HCN in PhCl contg. HCl and AlCl3 to give 75% 4,2,5-Br(MeO)2C6H2CHO (I) after hydrolysis with aq. HCl. Subsequent oxidn. of I afforded 4,2,5-Br(MeO)2C6H2CO2H, which was also produced in 48% yield by carbonation of 4,2,5-Br(MeO)2C6H2MgBr, prepd. from 4,2,5-Br(MeO)2C6H2Br and Mg in THF.
Those who give up essential liberties for temporary safety deserve neither liberty nor safety