The cis/trans mixture of the title compound of 9-amino-14,32-dichloro-5-methyl-26-oxa-4-thia-3,8,10,16,19-pentaazatetracyclo[25.2.2.212,15.02,6]tritriaconta-1(29),2,5,8,12,14,23,27,30,32-decaene-7,17-dione (Example 4) (60 mg), benzaldehyde (24 mg), sodium triacetoxyborohydride (30 mg), trimethyl orthoformate (0.2 mL) and acetic acid (0.1 mL), in 2 mL of DMF was stirred at room temperature for 16 hrs. Ethyl acetate (10 mL) and saturated sodium bicarbonate solution (10 mL) were added. Layers were separated after the mixture was well shaken. The organic layer was dried over anhydrous magnesium sulfate and solvent was evaporated in vacuo to give a crude product, which was purified by preparative HPLC to give 27 mg of the title compound as an inseparable mixture of cis/trans isomers.
