Boron trifluoride etherate → 1-Methyl-1,4-dihydro-2H-3-thia-2,4,5-triaza-phenanthrene 3,3-dioxide

Participants

Reaction Steps

Ethoxyethane—trifluoroborane (1:1; 32.3 μl, 0.26 mmol) was added dropwise to a solution of 4H-3-thia-2,4,5-triaza-phenanthrene 3,3-dioxide 406 (60 mg, 0.26 mmol) in dry THF (3 ml) under an atmosphere of N2. The mixture was stirred at room temperature for 1 h and then cooled to −78° C. Methyllithium (1.6M in Et2O; 1.61 ml, 2.57 mmol) was added dropwise and the mixture was stirred −78° C. for 1 h. The reaction was quenched with sat NH4Cl (2 ml) at -78° C. and the mixture was warmed to room temperature. The mixture was extracted with EtOAc and the residue was purified by preparative HPLC (acidic conditions 1) to give the title compound (18 mg, 28%).

Provenance & Evidence