Sodium Carbonate → 6-[({1-[2-(7-Fluoro-2-oxo-1(2H)-quinoxalinyl)ethyl]-4-piperidinyl}amino)methyl]-2H-pyrido[3,2-b][1,4]thiazin-3(4H)-one dihydrochloride

Participants

Reaction Conditions

Reaction Steps

A solution of 1-[2-(4-amino-1-piperidinyl)ethyl]-7-fluoro-2(1H)-quinoxalinone dihydrochloride (60 mg; 0.166 mmol) and 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]thiazine-6-carboxaldehyde (for a synthesis, see WO2004058144, Example 7(d)) (32 mg, 0.166 mmol) in MeOH (3 ml), chloroform (3 ml) and triethylamine (0.06 ml) was stirred at rt for 1 h then heated at 70° C. overnight. It was cooled and sodium triacetoxyborohydride (0.106 g; 0.5 mmol) was added and the mixture was stirred at rt for 5 h. More 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]thiazine-6-carbaldehyde (4 mg) was added and the mixture was stirred for 3 h at rt. Sodium triacetoxyborohydride (53 mg) was added and the mixture was stirred at rt for 72 h. Water and sodium carbonate solution were added and the mixture was extracted (3×) with 10% MeOH-DCM, dried (sodium sulphate), evaporated, and chromatographed on silica gel, eluting with 0-15% MeOH-DCM to give the free base of the title compound.

Provenance & Evidence