for the following products
(2Z)-5,6-dimethoxy-2-(pyridin-4-ylmethylidene)-2,3-dihydro-1H-inden-1-one | 2,3-Dihydro-5,6-dimethoxy-2-(4-pyridinylmethylene)-1H-inden-1-one | 5,6-Dimethoxy-2-(pyridin-4-yl)methyleneindan-1-one | Donepezil intermediate (I) and 4-[(5,6-Dimethoxy-1-indanone)-2-methyl] pyridine
