Azetidine → 6-(azetidine-1-carbonyl)-8-(1-(3,5-difluorophenylamino)ethyl)-2-morpholino-4H-chromen-4-one

Participants

Reaction Steps

2-(2,5-dioxopyrrolidin-1-yl)-1,1,3,3-tetramethylisouronium tetrafluoroborate (409 mg, 1.36 mmol) was added portionwise to a suspension of the enantiomer 2 of 8-(1-(3,5-difluorophenylamino)ethyl)-2-morpholino-4-oxo-4H-chromene-6-carboxylic acid ([α]D20°: −102°, enantiomer 2, see Example 7.0a) (450 mg, 1.05 mmol) and N-ethyl-N-isopropylpropan-2-amine (0.310 mL, 1.78 mmol) in DCM (5 mL) at RT under nitrogen. The resulting mixture was stirred at RT for 4 hrs. Azetidine (0.211 mL, 3.14 mmol) was then added to the mixture and stirring was maintained overnight. The mixture was diluted with DMF and concentrated to remove DCM. The reaction mixture was purified by preparative HPLC on a Waters X-Bridge system. The fractions were evaporated to dryness afford a white solid 6-(azetidine-1-carbonyl)-8-(1-(3,5-difluorophenylamino)ethyl)-2-morpholino-4H-chromen-4-one (300 mg, 61%). Mass Spectrum: M+H+ 470. [α]D20°: −113° in MeCN. NMR Spectrum (DMSOd6): 1.50 (d, 3H), 2.18-2.28 (m, 2H), 3.50-3.63 (m, 4H), 3.69-3.78 (m, 4H), 3.98-4.07 (m, 2H), 4.09-4.19 (m, 2H), 4.97-5.05 (m, 1H), 5.61 (s, 1H), 6.15 (d, 2H), 6.21 (t, 1H), 7.03 (d, 1H), 7.79 (d, 1H), 8.02 (d, 1H).

Provenance & Evidence