1,8-Diazabicyclo(5.4.0)undec-7-ene → 3-[7-(benzyloxy)-1,1-dioxido-4H-1,2,4-benzothiadiazin-3-yl]-4-hydroxy-1,1-dipropyl-2(1H)-naphthalenone

Participants

Reaction Conditions

Reaction Steps

A solution of the compound of Example 2E (300 mg, 0.547 mmol) in anhydrous pyridine (5.2 mL) was treated with 1,8diazabicyclo[5.4.0]undec-7-ene (82 μL, 0.55 mmol) and stirred at 140° C. for 18 hours, cooled to 25° C. and the pyridine removed by short path distillation under high vacuum (50° C./0.3 mm Hg). A solution of the residue in ethyl acetate was washed with water (2×) and saturated sodium chloride solution, dried (Na2SO4), filtered and concentrated in vacuo. The residue was chromatographed on silica gel, eluting with ethyl acetate in hexane to give the title compound (110 mg, 38%). 1H NMR (300 MHz, DMSO-d6): δ 8.11 (d, J=7.72 Hz, 1 H), 7.64 (m, 1 H), 7.41 (m, 8 H), 5.21 (s, 2 H), 2.14 (m, 2 H), 1.83 (m, 2 H), 0.87 (m, 2 H), 0.64 (m, 8 H).

Provenance & Evidence