Ethyl bromoacetate → 9-(Aminosulfonyl)fluorene-9-acetic acid ethyl ester

Participants

Reaction Steps

To a stirred, 15° C. suspension of sodium hydride (60% in mineral oil, 500 mg, 12.2 mmoL, 1 eq) in 50 mL of dry dimethylformamide (from molecular sieves) under nitrogen was added dropwise over 15 minutes a solution of (8) (3 g, 12.2 mmoL) in 100 mL of dimethylformamide. A solution of ethyl bromoacetate (2.0 g, 12.2 mmoL, 1 eq) in 20 mL of dimethylformamide was then added dropwise over 10 minutes. After 3 h at room temperature, the reaction was diluted with water (100 mL), acidified (pH 5) and extracted with ethyl acetate (3×200 mL). The combined organic extracts were washed with brine (5×100 mL), dried (MgSO4), filtered and evaporated. The crude oil was purified by chromatography on silica gel using a gradient of 10%-30% ethyl acetate in hexane to provide 1 g (25%) of product: mp 167°-170° C., 1H NMR (CDCl3) 7.8-7.2 (m, 8H, aromatic protons), 3.9 (broad single, 2H), 3.6 (s, 2H), 3.5 (q, 2H), 1.7 (t, 3H).

Provenance & Evidence