Furosemide → HCID 86613435, compound

Participants

Reaction Steps

Furosemide (5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoic acid), (10) (Aldrich) (0.050 mole) is added to a stirred solution of sodium bicarbonate (0.100 mole) and tetrabutylammonium hydrogen sulfate (0.050 mole) in water (100 mL) at ambient temperature. After 10 minutes 1,2-dichloroethane (100 mL) is added and then after 30 minutes O-iodomethyl S-ethyl carbonothioate (0.050 mole) in 1,2-dichloroethane (25 mL) is added over 15 minutes. The mixture is stirred for 1 hour at ambient temperature. The organic layer is separated, washed with water (50 mL), dried (magnesium sulfate), and the solvent is evaporated. The residue is stirred with diethyl ether (100 mL), insoluble material is filtered off and washed with diethyl ether. The combined ether phases is evaporated, and the residue may be crystallized to give O-(5-(aminosulfonyl)-4-chloro-2-[(2-furanylmethyl)amino]benzoyloxymethyl) S-ethyl carbonothioate (1005). See eg., Folkmann, et al., Synthesis, 1159 (1990), Method D.

Provenance & Evidence