Example 1
To a suspension of the SM (827 mg, 2.0 mmol) in CHCl3 (10 mL) was added DIEA (0.348 mL, 2.0 mmol) and 2,5-dioxopyrrolidin-1-yl 2-acetoxyacetate (560 mg, 2.6 mmol). The reaction mixture was stirred at RT for 30 min leading to a yellow solution, after which time the reaction mixture was concentrated. MeOH (5 mL) and H2O (6 mL) were added to form a slurry which was stirred at RT for 1 h. The resulting solid was filtered to provide the product as a light yellow solid. [1.04 g, 98%]
[Patent Reference: WO2012129344, page 132, (7.3 MB)]