Sodium borohydride reduction of succinimide in isopropanol, according to the Speckamp's procedure, gives 5-isopropoxy-2-pyrrolidinone. Condensation with 3-trifluoromethylbenzenesulfonyl chloride (2) is effected with n-butyllithium in tetrahydrofuran at low temperature to give RU-47067 in an overall yield of 38%.