Acetic Acid → 8-Amino-3-phenylsulfonylquinoline methanesulfonic acid salt

Participants

Reaction Conditions

Reaction Steps

A suspension of iron powder (26.7 g, 5 eq, 325 mesh) in THF (300 ml, 10 vol), water (30 ml, 1 vol) and acetic acid (19.2 ml, 3.5 eq) was heated to 50° C. 8-Nitro-3-phenylsulfonylquinoline (D4) (30 g, 1 wt) was added portionwise to the mixture over 30 min, keeping the temperature below 60° C. The reaction mixture was stirred at 50 to 55° C. for 60 min. Toluene (240 ml, 8 vol) was added, followed by water (60 ml, 2 vol) before cooling to 40° C. and filtering the mixture through a silica gel plug. The silica plug was washed with toluene (2×60 ml, 2 vol). The layers of the combined filtrate were separated and the organic layer concentrated in vacuo to ca 10 volumes. The reaction mixture was warmed to 77° C. then treated with methanesulfonic acid (7.42 ml, 1.2 eq) added over 15 min maintaining the temperature at 75 to 80° C. The resulting orange suspension was cooled slowly to ambient, stirred at ambient temperature for ca 2 h, then the product filtered and washed with toluene (3×60 ml). The resulting pink solid (D35) was dried in vacuo at ca 45° C. to constant weight. Yield: 34.17 g, 94%.

Provenance & Evidence