合成路线1

A new synthesis of atipamezole has been described: The cyclization of alpha,alpha'-dibromo-o-xylene (I) with acetylacetone (II) by means of NaOH and tetrabutylammonium bromide in toluene/water at 80 C under phase-transfer conditions gives the unstable diacetyl derivative (III), which presumably undergoes cleavage to afford 2-acetylindane (IV). The alkylation of (IV) with ethyl iodide and potassium tert-butoxide yields 2-acetyl-2-ethylindane (V), which is brominated with Br2 to give 2-(bromoacetyl)-2-ethylindane (VI). Finally, this compound is cyclized with formamide at 160 C [some 2-ethyl-2-(4-oxazolyl)indane is also formed but is easily eliminated]; the cyclization can also be carried out with formamidine in liquid ammonia.