Diisopropylethylamine → tert-butyl 3-{[3'-fluoro-4'-({4-[(3S)-7-fluoro-3-methyl-2-oxo-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-1-yl]piperidin-1-yl}carbonyl)biphenyl-2-yl]oxy}-2,2-dimethylpropanoate

Participants

Reaction Steps

At room temperature, to an N,N-dimethylformamide solution (10 ml) of (3S)-7-fluoro-3-methyl-1-piperidin-4-yl-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one (Reference Example 2) (434 mg) and 2′-(3-tert-butoxy-2,2-dimethyl-3-oxopropoxy)-3-fluorobiphenyl-4-carboxylic acid (636 mg) were added 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (683 mg) and diisopropylethylamine (0.855 ml), followed by stirring for 24 hours. The reaction solution was poured into water (40 ml), and stirred for 6 hours. The precipitate was collected by filtration and dried to afford tert-butyl 3-{[3′-fluoro-4′-({4-[(3S)-7-fluoro-3-methyl-2-oxo-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-1-yl]piperidin-1-yl}carbonyl)biphenyl-2-yl]oxy}-2,2-dimethylpropanoate (940 mg).

Provenance & Evidence