METHOD FOR PREPARING N, N'-DISUBSTITUED CYCLIC UREAS

摘要

Disubstituted cyclic ureas IV are prepared by reductive alkylation of I with aldehydes R22-CHO or R23-CHO in presence of a reducing agent to form II (step 1), followed by cyclocarbonylation of II to form III (step2) and deprotection of III to form the diol IV (step 3), according to the above schemes. These cyclic ureas IV are useful as HIV protease inhibitors.