2-hydroxymethyl-8-phenethyl-1,4-dioxa-8-azaspiro[4,5]decane (compound 1, 50 gm, 0.18 mole) was dissolved in toluene (300 ml) at room temperature. To this 44 gms of 2-chloro-4-bromophenol in toluene (150 ml) was added at room temperature 28° C. in the presence of ParaToluenesulfonic Acid (PTSA, 3.5 gm). Reaction mixture was refluxed with stirring for 13 hrs. It was then cooled and filtered. The filtrate was given water wash to bring the pH to neutral. Toluene was removed under vacuum to obtain a thick brick red colored product 95% yield.
