Boron trifluoride → HCID 58497238, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of step 4 product (250 mg, 0.552 mmol) in triethyl orthoformate (9.09 ml, 55.2 mmol) was added BF3 etherate (0.699 μl, 5.52 μmol) and the mixture stirred at 110° C. for overnight. The reaction mixture was diluted with EtOAc and washed with NaHCO3 (aq), organic layer was dried, and concentrated. The residue was purified on silica gel column eluting a gradient of 8-70% EtOAc in hexane to afford 3-(4-{5-[(4-chlorophenyl)sulfanyl]-2-(1-ethyl-1H-pyrazol-3-yl)-1-methyl-1H-imidazol-4-yl}phenyl)-1,2,4-oxadiazole (130 mg; more polar; the major regioisomer. There was also a minor regioisomer that was the subject of the next example). 1H NMR (500 MHz), [CDCl3]: 8.78 (s, 1H), 8.28 (m, 2H), 8.15 (m, 2H), 7.55 (m, 1H), 7.22 (m, 2H), 7.06 (m, 2H), 6.95 (m, 1H), 4.28 (q, 2H), 4.00 (s, 3H), 1.60 (t, 3H). LCMS: [M+1]+=463.1 (rt=1.16 min). Human FAAH lysate assay: IC50=28.7 nM.

Provenance & Evidence