8-fluoro-3-(3-hydroxypropyl)-N-methoxy-N-methyl-3-phenyl-3a,4-dihydro-3H-pyrazolo[5,1-c][1,4]benzoxazine-2-carboxamide → 1-[8-fluoro-3-(3-hydroxypropyl)-3-phenyl-3a,4-dihydro-3H-pyrazolo[5,1-c][1,4]benzoxazin-2-yl]ethanone

8-Fluoro-3-(3-hydroxypropyl)-N-methoxy-N-methyl-3-phenyl-3a,4-dihydro-3H-pyrazolo[5,1-c][1,4]benzoxazine-2-carboxamide (5-7; a racemic mixture, 2.6 g, 6.29 mmol) was dissolved in anhydrous THF (50 mL) and cooled to −78° C. Methyllithium (11.8 mL, 3M in diethylether, 18.9 mmol) was added and the reaction stirred to 25° C. Upon completion the reaction was quenched by the addition of NH4Cl (50 mL) and extracted with EtOAc (3×50 mL). The combined organic extracts were dried (MgSO4), filtered and concentrated. Flash column chromatography (ISCO Redisep 0-100% EtOAc/hexanes gradient) provided 1-[8-fluoro-3-(3-hydroxypropyl)-3-phenyl-3a,4-dihydro-3H-pyrazolo[5,1-c][1,4]benzoxazin-2-yl]ethanone (5-8; a racemic mixture). 1H NMR (300 MHz, CDCl3) δ 7.28 (m, 4H), 7.07 (m, 2H), 6.78 (dd, J=8.9, 5.1 Hz, 1H), 6.58 (ddd, J=8.9, 8.2, 3.1 Hz, 1H), 4.15 (dd, J=10.5, 3.5 Hz, 1H), 3.75 (m, 2H), 3.71 (dd, J=10.8, 3.5 Hz, 1H), 2.95 (t, J=10.8 Hz, 1H), 2.55 (dt, J=13.0, 4.0 Hz, 1H), 2.55 (s, 3H), 2.37 (dt, J=13.0, 4.0 Hz, 1H), 1.74 (m, 1H), 1.42 (m, 1H); MS (M+H+, C21H21FN2O3) 369.3 found 369.4 required. This compound was resolved on the Chiracel OD column using MeOH as eluant into its separate enantiomers.

1. customUpon completion the reaction was quenched by the addition of NH4Cl (50 mL)
2. extractionextracted with EtOAc (3×50 mL)
3. dry with materialThe combined organic extracts were dried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated

ORD record

ord-c7fbd8b4dc9b43a5bac23dc891131575

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07632833B2