Chloride → 4-{[4-(5-chloro-2-methoxy-benzene-sulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl]-amino}-benzoic acid ethyl ester

Participants

Reaction Steps

A suspension of 4-(5-chloro-2-methoxy-benzenesulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylic acid (1.0 g, 2.6 mmol) in acetone (130 mL) and tetrahydrofuran (30 mL) was treated with triethylamine (0.5 g, 0.68 mL, 1.9 equiv.) and stirred at room temperature overnight. A solution of cianuric chloride (596 mg, 3.2 mmol, 1.24 equiv.) in acetone (20 mL) was added dropwise over a period of 1 hour. The reaction mixture was stirred at room temperature for 4 hours, 4-amino-benzoic acid ethyl ester (775 mg, 4.7 mmol, 1.8 equiv.) was then added. The reaction mixture was stirred at room temperature overnight, the solvents were then removed. The residue was purified by flash chromatography, to yield 4-{[4-(5-chloro-2-methoxy-benzene-sulfonyl)-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl]-amino}-benzoic acid ethyl ester as a white solid, 0.91 g (66%). δH (300 MHz; CDCl3) 8.10 (1H, d), 8.03-8.07 (3H, m), 7.92 (1H, bs), 7.73 (2H, d), 7.70 (1H, d), 7.67 (1H, d), 7.53 (1H, d), 7.50 (1H, d), 4.37 (2H, q), 4.03 (2H, m), 3.88 (2H, m), 3.56 (3H, s), 1.40 (3H, t).

Provenance & Evidence