Benzenesulfonamide, 2-amino-5-fluoro- (7CI,8CI,9CI) synthesis

Yield:1992-90-1 96%

Reaction Conditions:

with tin(II) chloride dihdyrate in ethanol; for 1.2 h;Reflux;

Steps:

2.1 Step 1. Preparation of 2-amino-5-fluorobenzenesulfonamide

Add 4.40g (20mmol) of 5-fluoro-2-nitrobenzenesulfonamide to a 150mL double-necked round bottom flask at room temperature, add 70mL of absolute ethanol and 6.78g (30mmol) of stannous chloride dihydrate in turn, and heat to reflux for 1.2h , The absolute ethanol was removed under reduced pressure, 30mL ethyl acetate was added to the flask, and after stirring for 10 min, the mixture was poured into ice water, sodium bicarbonate solid was added, the pH was adjusted to 8, filtered under reduced pressure and washed with ethyl acetate The filtrate was collected, and the solvent was removed under reduced pressure to obtain 3.65 g of white solid 2-amino-5-fluorobenzenesulfonamide with a yield of 96%.

References:

CN111410638,2020,A Location in patent:Paragraph 0032-0034