Dear Abdullah,

Yes indeed. Please see attached file.

Rafik

it will demethylate but selectivity is not clear

this is my request I need two demethylated groups of four.

this transformation is only possible with enzymatic hydrolysis

In fact, BBr3 is a good one for demethylation of OCH3. You an find a number of reports from the internet.

Actually it is not possible to get BBr3 from suppliers.

Yes, always it should with a solvent. But instead of BBr3 dms you can prefer BBr3 dcm. Dimethyl sulfate itself a very good methylating agent.

The methoxy group ortho to the carbonyl in ring C will break easily. The middle methoxy in ring A is rather reactive and could be cleaved by a number of reagents including Bronsted and Lewis acids.