Kindly specify the structure for better understanding.

thank you for reply

any structure with a quinoline heterocycle bearing two or more Methoxy groups where regioselective  demethylation was carried out. 

Can use following conditions

1) 48 % HBr / water at 80 - 100°C

2) AlCl3/ NaI

3) 48% HBr/ tetra-n-butylphosphonium bromide

4) Tetra methyl ammonium hydroxide/ AlCl3

5) AlCl3/ Thiourea

All the best

Thiol-based methods

BCl3-based methods

thank you so much, in fact, it is to do comparaison between our work and what it was previously done

regards