Selective propionylation of veratrole to 3,4-dimethoxypropiophenone using zeolite H-beta catalysts

Use of Solid Catalysts in Friedel−Crafts Acylation Reactions

“…However, this statement must be carefully considered each time, since the alkoxy group represents a good donor for the acid sites of the catalyst and it can interact so strongly with the catalyst itself that the original activity of both aromatic ether and catalyst can be greatly lowered. The Friedel−Crafts acylation of aromatic ethers has attracted considerable interest in organic synthesis and in industrial chemistry because of the widespread application of the corresponding ketones as valuable intermediates in fine chemistry. ,− An example is the selective acetylation of 2-methoxynaphthalene (2MN) at the carbon in position 6 owing to the great interest in 2-methoxy-6-acetylnaphthalene (2Ac6MN), an intermediate in the preparation of the anti-inflammatory drug ( S )-Naproxen. , …”

“…The regioselective propanoylation of veratrole ( 75 ) to 3,4-dimethoxypropiophenone ( 77 ) with propanoyl chloride ( 76 ) ( 75 / 76 ratio = 1) was explored by Singh et al over HBEA, HMOR, HY, and REY zeolites in comparison with AlCl 3 (Scheme , n = 1). In all experiments, 3,4-dimethoxypropiophenone was the main product accompanied by small amounts of other (consecutive) products.…”