1,8-Diazabicyclo(5.4.0)undec-7-ene → 1-(5-Tert-butylisoxazol-3-yl)-3-(2-fluoro-5-hydroxyphenyl)urea

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of phenyl 5-tert-butylisoxazol-3-ylcarbamate (prepared as described in Example 270A) (260 mg, 1 mmol) and 3-amino-4-fluorophenol (127 mg, 1 mmol) in acetonitrile (15 mL) at rt, was added DBU (0.3 mL, 2 mmol). The mixture was heated at 50° C. for 1 h. The reaction mixture was cooled to rt, concentrated under reduced pressure, and the residue purified via silica gel column chromatography to afford 1-(5-tert-butylisoxazol-3-yl)-3-(2-fluoro-5-hydroxyphenyl)urea (200 mg, 68%) as a solid. 1H NMR (400 MHz, DMSO-d6) δ9.68 (m, 2H), 8.41 (m, 1H), 7.68 (m, 1H), 6.56-6.65 (m, 2H), 6.45 (s, 1H), 1.29 (s, 9H); LC-MS (ESI) m/z 294 (M+H)+.

Provenance & Evidence