Isobutylamine → 3-(3-Fluoro-4-pyrrolidin-1-ylmethyl-phenyl)-3-hydroxy-cyclobutanecarboxylic acid isobutyl-amide

A THF solution of crude ˜0.12M intermediate 15, 3-(3-fluoro-4-(pyrrolidin-1-ylmethyl)phenyl)-3-hydroxycyclobutanecarboxylic acid (160 mL, 19.3 mmol) was combined with isobutylamine (3.8 mL, 38.2 mmol) and T3P (50% wt in EtOAc, 13.8 mL, 23.2 mmol) and stirred at room temperature for 20 h. The mixture was made basic with saturated aqueous NaHCO3 and EtOAc (50 mL) was added. The phases were separated and the aqueous phase was extracted again with EtOAc. The combined organics were washed with brine, dried over MgSO4 and concentrated to yield an orange oil. Flash chromatography on a 2″×4″ silica gel column flushing first with EtOAc (1 L) and 10% MeOH/EtOAc (500 mL) to remove higher Rf impurities followed by elution with an additional 500 mL of 10% MeOH/EtOAc and 500 mL 20% MeOH/EtOAc afforded 4.22 g (63%) of the title compound as an waxy, orange solid: Rf=0.3 (30% MeOH/EtOAc); 1H NMR (CDCl3) δ 7.34 (t, J=7.9 Hz, 1H), 7.20-7.13 (m, 2H), 5.84 (br s, 1H), 3.66 (d, JH-F=1.3 Hz, 2H), 3.11 (t, J=6.4 Hz, 2H), 2.84-2.76 (m, 3H), 2.55-2.45 (m, 6H), 1.81-1.72 (m, 4H), 0.91-0.87 (d @ 0.90 (J=6.6 Hz, 6H) overlapping m (1H)); LRMS m/z Calcd for C20H29FN2O2, 348.5, found, 349.4 (M+H) APCI.

1. additionwas added
2. customThe phases were separated
3. extractionthe aqueous phase was extracted again with EtOAc
4. washThe combined organics were washed with brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated
7. customto yield an orange oil
8. customFlash chromatography on a 2″×4″ silica gel column flushing first with EtOAc (1 L) and 10% MeOH/EtOAc (500 mL)
9. customto remove higher Rf impurities
10. washfollowed by elution with an additional 500 mL of 10% MeOH/EtOAc and 500 mL 20% MeOH/EtOAc

ORD record

ord-1b386b5ff84942d6841991ba17492f4b

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08158673B2