A mixture of 430D (41 mg, 0.10 mmol), Et3N (56 μl, 0.40 mmol) and DPPA (43 μl, 0.20 mmol) in dioxane (1 ml) was stirred at rt for 2 h under argon, 2-morpholin-4-yl-ethanol (49 μl, 0.40 mmol) was added. The resulting mixture was heated to 80° C. for 2 h, cooled to rt. Treated with EtOAc (20 ml), the mixture was washed with H2O (2×5 ml) and brine (10 ml), dried with Na2SO4. Removal of the solvent followed by flash chromatography of the residue on silica gel (3%-5% MeOH—CH2Cl2) gave 432A (47 mg, 88%) as a light yellow solid. It has a retention time of 5.35 min (∠Cl, 8 min. run). MS Found: (M+H)+=543.2
