Diisopropylethylamine → 6-({4-[3-(7-Methoxy-2-oxo-2H-3,1-benzoxazin-1(4H)-yl)propyl]piperazin-1-yl}methyl)-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one

Participants

Reaction Steps

7-Methoxy-1-(3-piperazin-1-ylpropyl)-1,4-dihydro-2H-3,1-benzoxazin-2-one trifluoroacetate (Intermediate 118, crude, 886 mg, 1.66 mmol) was converted to the free base with N,N-diisopropylethylamine and reacted with 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehyde (WO 2004/058144) (220 mg, 1.23 mmol) and sodium triacetoxy borohydride (521 mg, 2.46 mmol) as described for Example 55 to give the free base of the product as a pink foam after chromatography on silica gel with dichloromethane/methanol (93:7), 86 mg (21%).

Provenance & Evidence