TEA (1.5 mL, 10.9 mmol) was added to a suspension of the product of Step 33b (2.7 g, 10 mmol) in CH2Cl2 (100 mL). Diphenylchlorophosphate (2.08 mL, 10 mmol) was added and the resulting solution is stirred at room temperature for 30 minutes. To this solution is added a solution of (R)-3-aminoquinuclidine (1M in DMF, 9.1 mL, 9.1 mmol). The resulting solution is stirred overnight at room temperature. MeOH is added and the mixture is poured through a column of AG50W×2 ion exchange resin (H+ form). The resin is washed with MeOH, then the product is eluted with 5% TEA in MeOH. The eluent is evaporated to dryness and the resulting solid is triturated with ether and dried in vacuo to yield the desired product (2.4 g, 71%). Alternatively, these compounds can be converted to their hydrochloride salts and crystallized from MeOH/IPA. MS for C18H19ClN2OS2 (ESI) (M+H)+ m/z 379.
