Phosphorus oxychloride → HCID 11438401, compound

Participants

Reaction Steps

To a flask containing 20 ml of POCl3 at 120° C. oil bath was carefully added a solution of 5 g (17 mmol) crude compound 4 and 2.6 ml of 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) (17 mmol) in 20 ml of methylene chloride. After the addition, the reaction mixture was refluxed for one hour. The resulting mixture was concentrated to dryness and diluted with ethyl acetate. Saturated aqueous NaHCO3 was carefully added to the solution to adjust pH to 5-6. The organic phase was separated and the aqueous phase was extracted with the same volume of EtOAc. The combined organic phases were then washed with brine and dried with magnisium sulfate, filtered and concentrated to dryness. The residue was purified with flash chromatography (silica gel, 5% EtOAc/hexane) to get 1.8 g of compound 5 and 850 mg of a mixture of compound 5 and unreacted compound 3. 1H NMR (CDCl3): δ 7.93 (d, 2H, J=6.7 Hz), 7.48 (d, 1H, J=1.36 Hz), 7.09 (d, 1H, J=1.5 Hz), 7.00 (m, 6H), 2.59 (s, 3H). MS: 314.1

Provenance & Evidence