3-(4-Aminophenyl)-6-fluoro-7-(methylamino)-2,3-dihydrobenzo[e][1,3]oxazin-4-one → 1-(5-chlorothiophen-2-ylsulfonyl)-3-(4-(6-fluoro-7-(methylamino)-4-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)phenyl)urea

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(4-aminophenyl)-6-fluoro-7-(methylamino)-2,3-dihydrobenzo[e][1,3]oxazin-4-one (Ex. 4) (130 mg, 0.45 mmol) and (5-Chloro-thiophene-2-sulfonyl)-carbamic acid ethyl ester (150 mg, 0.53 mmol, 1.2 eq) in dry 1,4-dioxan (3 mL) was heated at 110° C. for 2 hr. Upon cooling, the reaction was concentrated in vacuo and the crude residue was purified by HPLC (C-18) to give 86 mg (37%) of pure 1-(5-chlorothiophen-2-ylsulfonyl)-3-(4-(6-fluoro-7-(methylamino)-4-oxo-2H-benzo[e][1,3]oxazin-3(4H)-yl)phenyl)urea. RP-HPLC: 2.49 min; ES-MS (M+H)+=511.0; 1H-NMR (MeOH-d4) δ (ppm): 2.8 (s, 3 H), 5.4 (s, 2 H), 6.2 (d, 1 H), 6.9 (d, 2 H), 7.1 (d, 2 H), 7.3 (d, 1 H), 7.4 (d, 1 H), 7.5 (d, 2 H).

Provenance & Evidence