Example 1
To a solution of triphosgene (26.4 mg, 0.090 mmol) in ACN (1 mL) at -5 C was added a solution of B (91.6 mg, 0.26 mmol) and TEA (73.2 uL) in ACN (1 mL) over 5 min. Then was added a solution of A (125 mg, 0.090 mmol) and TEA (73.2 uL) in ACN (1 mL). The reaction mixture was slowly warmed to RT and stirred for 3 h. The mixture was concentrated and the resulting material was purified by RP-HPLC to provide the product as a flaky shiny white solid. [132 mg, 75%]
[Patent Reference: WO2002016360, page 18, (1.3 MB)]