合成路线1

Condensation of 2-(4-methylphenyl)ethanol (I) with t-Bu-bromoacetate (II) in toluene in the presence of NaOH and tetrabutylammonium bromide (TBAB) provides ethoxyacetic acid derivative (III), which is converted into acetamide (V) by reaction with oxalyl chloride (IV) in toluene/DMF followed by treatment with NH4OH. Reduction of (V) by reaction with borane-tetrahydrofuran (BH3·THF) in THF yields ethanamine (VI), which is then coupled to chlorosulfonyl derivative (VII) in CH2Cl2 in the presence of TEA to afford compound (VIII). Reduction of the ester group of (VIII) by treatment with diisobutylaluminium hydride (DIBAL) in toluene furnishes aldehyde (IX), which is finally subjected to a reductive amination with benzothiazol derivative (X) by means of NaCNBH3 in MeOH/HOAc.