合成路线1

Assembly of the target compound: The reaction of methyl 3-bromopropionate (XVII) with ethylmagnesium bromide (XVIII) and Ti(iPrO)4 gives 1-(2-bromoethyl)cyclopropan-1-ol (XIX), which is brominated by NBS in CCl4 to yield 1,5-dibromo-3-pentanone (XX). The reaction of (XX) with ethylene glycol (XXI), HC(OEt)3 and PPTS affords the cyclic ketal (XXII), which is cyclized with the indolinone intermediate (VII) by means of NaH in DMF to provide the spiro compound (XXIII). The deprotection of (XXIII) with PPTS in acetone/water gives the spiranic diketone (XXIV), which is selectively reduced with NaBH4 in methanol to yield the spiro cyclohexanol (XXV). The condensation of (XXV) with 4-(2-chloroethyl)morpholine (XXVI) by means of NaH in hot toluene affords the corresponding ether (XXVII), which is debenzylated by means of Li/NH3 to provide intermediate (XXVIII) with a free NH group. Finally, the sulfonation of (XXVIII) with intermediate chlorosulfonyl benzamide (XVI) by means of potassium tert-butoxide gives the target sulfonyl benzamide compound.