Diisopropylethylamine → 7-Fluoro-3-methyl-1-[2-(4-{[(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-6-yl)methyl]amino}piperidin-1-yl)ethyl]quinazoline-2,4(1H,3H)-dione

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Reaction Steps

1-[2-(4-Aminopiperidin-1-yl)ethyl]-7-fluoro-3-methylquinazoline-2,4(1H,3H)-dione trifluoroacetate salt (Intermediate 134) (0.476 mmol, 380 mg crude) was converted to the free base with N,N-diisopropylethylamine (0.5 mL, 3.0 mmol) and reacted with 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehyde (WO 2004/058144) (102 mg, 0.571 mmol) and sodium triacetoxy borohydride (222 mg, 1.05 mmol) as described for Example 55. The reaction was diluted with dichloromethane and water. The layers were separated. The aqueous layer was extracted with dichloromethane twice. The combined organic layers were dried over magnesium sulfate and evaporated at reduced pressure. Chromatography on silica gel using methanol in dichloromethane (0-9%) with 1% concentrated ammonium hydroxide (aqueous) gave the product as a waxy material. This material was taken up in dichloromethane and washed well with water. The organic phase was dried over magnesium sulfate and evaporated to obtain the title compound as a colorless solid (48 mg, 21%).

Provenance & Evidence