converting 2 - phenylethanol into 3, 4 - dihyro - 1H - isochromene by using a set of cyclisation steps halogenating said 3, 4 - dihyro - 1H - isochromene to form 2 - (2 - bromoethyl)benzaldehyde by using bromine or DBDMID in the halogenation steps, condensing said 2 - (2 -bromoethyl)benzaldehyde to form said 2 - [2-(l,3 - dioxo - 1,3 - dihydro - 2H -isoindol - 2 - yl)ethyl]benzaldehyde, by using alkali salt of compound like 1H -isoindole - I, 3(2H) - dione or adding alkali hydroxide or alkali carbonate or mixture thereof to this compound. Un-substituted 2-[2-(l,3-dioxo-l,3-dihydro-2H-isoindol-2-y])ethyl]benzaldehyde is an important intermediate for 4-[2-(dipropylamino)ethyl]-l,3-dihydro-2H-indol-2-one an non-ergoline dopamine agonist used in the treatment of Parkinson"s disease and in the treatment of restless legs syndrome (RLS).
