Potassium Phosphate, Tribasic → (S)-7-(2-fluoropyridin-3-yl)-3-methoxy-2',6'-dihydrospiro[chromeno[2,3-c]pyridine-5,3'-[1,4]oxazin]-5'-amine

Temperature

100 °C

A microwave vial was charged with (S)-7-bromo-3-chloro-2′,6′-dihydrospiro[chromeno[2,3-c]pyridine-5,3′-[1,4]oxazin]-5′-amine (1.2557 g, 3.30 mmol), 2,2-dimethylpropan-1-ol (0.914 g, 10.37 mmol), 18-crown-6 (0.087 g, 0.330 mmol), and potassium hydroxide (0.925 g, 16.50 mmol) (freshly ground). The vial was flushed with Ar (g), then dioxane (6.60 mL) was added. The vial was sealed and placed in a 120° C. oil bath and stirred for 24 hours. The reaction mixture was diluted with water and a small amount of brine. The aq. mixture was then extracted with EtOAc (3×). The combined organic extracts were dried over sodium sulfate, filtered, and concentrated. The residue was purified by chromatography (0-100% EtOAc/hexanes) to afford 0.657 g of (S)-7-bromo-3-methoxy-2′,6′-dihydrospiro[chromeno[2,3-c]pyridine-5,3′-[1,4]oxazin]-5′-amine as a yellow solid. Step 2: A microwave vial was charged with (S)-7-bromo-3-methoxy-2′,6′-dihydrospiro[chromeno[2,3-c]pyridine-5,3′-[1,4]oxazin]-5′-amine (0.065 g, 0.173 mmol), 2-fluoropyridin-3-ylboronic acid (0.049 g, 0.346 mmol), potassium phosphate (0.110 g, 0.518 mmol), and bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (6.12 mg, 8.64 μmol). The vial was flushed with Ar (g), dioxane (0.648 mL) and water (0.216 mL) were added in sequence. The vial was sealed and heated in a Biotage Initiator microwave reactor for 30 min at 100° C. The reaction was diluted with ethyl acetate and washed with water. The aqueous layer was extracted with EtOAc, and the combined organic layers were washed with brine, dried with sodium sulfate, filtered, and concentrated. The material was purified via column chromatography (0-10% MeOH/EtOAc) to afford 65 mg of (S)-7-(2-fluoropyridin-3-yl)-3-methoxy-2′,6′-dihydrospiro[chromeno[2,3-c]pyridine-5,3′-[1,4]oxazin]-5′-amine as a light yellow solid.

1. customThe vial was flushed with Ar (g), dioxane (0.648 mL) and water (0.216 mL)
2. additionwere added in sequence
3. customThe vial was sealed
4. additionThe reaction was diluted with ethyl acetate
5. washwashed with water
6. extractionThe aqueous layer was extracted with EtOAc
7. washthe combined organic layers were washed with brine
8. dry with materialdried with sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customThe material was purified via column chromatography (0-10% MeOH/EtOAc)

ORD record

ord-f33866c8a0524a848eb005b96714ccd3

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09012446B2