Hydrochloric Acid → 4-(2-Diisopropylamino-ethylamino)benzenesulfonic acid 2-butyrylaminobenzothiazol-6-yl ester hydrochloride

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Reaction Conditions

Reaction Steps

A solution of 4-fluorobenzenesulfonic acid 2-butyrylaminobenzothiazol-6-yl ester (intermediate 78) (100 mg, 0.2 mmol) and N,N-diisopropylethylene-diamine (185 μl, 1.01 mmol) in 3 ml of N-methylpyrrolidone in a 5 ml microwave vial, equipped with a magnetic bar, is heated for 10 minutes at 150° C. by microwave. The reaction medium is extracted with ethyl acetate and washed with water. The organic phase is dried over magnesium sulfate, filtered and then evaporated to dryness. The residue obtained is purified by chromatography on Merck silica (40-63 μm). After evaporating off the solvent, 41 mg of a colorless oil (crystallizes when dry) are obtained. The product is dissolved in a minimum amount of ethyl acetate, and 4 N hydrochloric acid as a solution in dioxane is then added. The medium precipitates, and is concentrated, taken up in water and then filtered through a Milex 45 μm filter. The solution precipitates, and 31 mg (28% yield) of 4-(2-diisopropylamino-ethylamino)benzenesulfonic acid 2-butyrylaminobenzothiazol-6-yl ester hydrochloride are obtained after vacuum filtration and then drying under vacuum at 40° C.

Provenance & Evidence