Pyridine → 1,1-Dimethylethyl (1-{[(1R)-3,8-dioxo-1,2-dihydro-3H,8H-2a,5,8a-triazaacenaphthylen-1-yl]methyl}-4-piperidinyl)carbamate

Participants

Reaction Conditions

Reaction Steps

A solution of [(1S)-3,8-dioxo-1,2-dihydro-3H,8H-2a,5,8a-triazaacenaphthylen-1-yl]methyl methanesulfonate (1.05 g, 3.53 mmol) in dry acetonitrile (50 ml) at room temperature under argon was treated with pyridine (0.343 ml, 4.24 mmol), followed by 1,1-dimethylethyl 4-piperidinylcarbamate (0.884 g, 4.24 mmol). The mixture was heated at 70° C. for 1.5 h and then at 90° C. for 3 h. LCMS showed ˜25% of product. So 0.5 eq of pyridine and 0.5 eq of 1,1-dimethylethyl 4-piperidinylcarbamate were added and the reaction was heated at 90° C. overnight and then stirred at room temperature for 2 days. The reaction was complete. The solvent was evaporated and the residue partitioned between sat NaHCO3 and 20% methanol/dichloromethane (100 ml/100 ml). The layers were separated and the aqueous layer was extracted with 20% methanol/dichloromethane again (2×100 ml). The combined organic extracts were dried on magnesium sulphate, filtered and evaporated to afford 1.7 g of crude which was purified by silica chromatography using a 0-5% methanol/dichloromethane gradient to afford the product as a yellow solid (0.57 g, 40.2%).

Provenance & Evidence