Dimethylformamide → HCID 67436749, compound

Temperature

90 °C

A 50 ml RB flask was charged with 7′-bromo-4′-fluoro-2′-methoxy-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine (806 mg, 2.050 mmol), 2-fluoropyridin-3-ylboronic acid (433 mg, 3.07 mmol), PdCl2(Cy2PC6H4NMe2)2 (72.6 mg, 0.102 mmol), then dioxane (10 ml) and potassium carbonate (1M solution in water; 6.15 ml, 6.15 mmol). The mixture was stirred at 85° C. for 1 hr. The reaction mixture was cooled to RT, diluted with EtOAc and organic layer was separated and concentrated in vacuo. The residue was treated with 3 ml of EtOH and precipitated solid was filtered off, washed with ethanol and dried on air to afford 514 mg (61%) of pure desired product. The filtrate was concentrated and purified by chromatography [5-80% DCM./MeOH/NH4OH (90:10:1) in DCM] to afford additional 300 mg (35%) of the product. Step 2: To a suspension of 4′-fluoro-7′-(2-fluoropyridin-3-yl)-2′-methoxy-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine (2.178 g, 5.32 mmol) in DCM (43 mL) boron tribromide (1.509 mL, 15.96 mmol) was added dropwise at RT. The mixture was stirred 2 hrs at RT, the mixture was cooled to 0° C. and quenched by addition of 5 ml of methanol dropwise. The resulting white suspension was stirred for 20 min at 0° C., then sat. aq. NaHCO3 (˜5 ml) was added followed by addition of 25% aq. ammonia (˜15 ml). The mixture was stirred for 30 min, then DCM was removed in a stream of nitrogen. The mixture was diluted with water (10 ml) and 25% ammonia (10 ml) and filtered. The white solid was washed with water twice, then dried for 3 hrs on air, then in vacuo overnight to give 2-amino-4′-fluoro-7′-(2-fluoropyridin-3-yl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2′-ol (2.08 g, 5.26 mmol, 99% yield). Step 3: To a suspension of 2-amino-4′-fluoro-7′-(2-fluoropyridin-3-yl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2′-ol (1.91 g, 4.83 mmol) in DCM (24.16 ml) TEA (1.347 ml, 9.66 mmol) and N-(5-chloropyridin-2-yl)-1,1,1-trifluoro-N-((trifluoromethyl)sulfonyl)methanesulfonamide (2.087 g, 5.31 mmol) were added at RT. The mixture was stirred for 1 hr at RT and the mixture became homogeneous. The reaction mixture was washed twice with 2N NaOH solution, brine, filtered through the pad of celite and concentrated to leave 2-amino-5′-fluoro-2′-(2-fluoropyridin-3-yl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-7′-yl trifluoromethanesulfonate (2.04 g, 3.87 mmol, 80% yield) as a creamy solid which was used without further purification. Step 4: A sealable tube was charged with 2-amino-5′-fluoro-2′-(2-fluoropyridin-3-yl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-7′-yl trifluoromethanesulfonate (500 mg, 0.948 mmol), tetrakis(triphenylphosphine)palladium (0) (219 mg, 0.190 mmol), copper(I) iodide (72.2 mg, 0.379 mmol), DMF (4.5 mL), trimethyl((3-methyloxetan-3-yl)ethynyl)silane (479 mg, 2.84 mmol) and DIPA (1.3 ml, 9.48 mmol). The vial was sealed and stirred at 90° C. for 18 hrs. The mixture was diluted with EtOAc (10 ml) and washed twice with water (5 ml) and brine. The organic layer was concentrated and purified by chromatography (30-50% DCM/MeOH/NH4OH in DCM) to afford racemic 4′-fluoro-7′-(2-fluoropyridin-3-yl)-2′-((3-methyloxetan-3-yl)ethynyl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine (117 mg, 0.247 mmol, 26.1% yield). Step 5: The final compounds (R)-4′-fluoro-7′-(2-fluoropyridin-3-yl)-2′-((3-methyloxetan-3-yl)ethynyl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine and (S)-4′-fluoro-7′-(2-fluoropyridin-3-yl)-2′-((3-methyloxetan-3-yl)ethynyl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine were obtained from racemic 4′-fluoro-7′-(2-fluoropyridin-3-yl)-2′-((3-methyloxetan-3-yl)ethynyl)-5,6-dihydrospiro[[1,3]oxazine-4,9′-xanthen]-2-amine using similar chiral separation conditions as described herein for intermediate 10.

1. customwas used without further purification
2. customThe vial was sealed
3. washwashed twice with water (5 ml) and brine
4. concentrationThe organic layer was concentrated
5. custompurified by chromatography (30-50% DCM/MeOH/NH4OH in DCM)

ORD record

ord-7a89172a81fb49b9939679fd7586fde3

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09012446B2