Methyl Ethyl Ketone → (3-{2-[4-(2,4-Dimethylphenyl)piperazine-1-carbonyl]-5-(1,1-dioxo-1lambda6-isothiazolidin-2-yl)phenoxy}propyl)carbamic acid tert-butyl ester

Participants

Reaction Steps

To a mixture of [4-(2,4-dimethylphenyl)piperazin-1-yl][4-(1,1-dioxo-1λ6-isothiazolidin-2-yl)-2-hydroxyphenyl]methanone (241 mg) described in Example 124, (3-bromopropyl)carbamic acid tert-butyl ester (200 mg) and cesium carbonate (548 mg) was added 2-butanone (4 mL), and the mixture was stirred with heating under reflux for 4 hr. Water was added to the reaction mixture, the mixture was extracted with ethyl acetate, and the solvent was evaporated. The obtained residue was purified by column chromatography (ethyl acetate:hexane) to give (3-{2-[4-(2,4-dimethylphenyl)piperazine-1-carbonyl]-5-(1,1-dioxo-1λ6-isothiazolidin-2-yl)phenoxy}propyl)carbamic acid tert-butyl ester (221 mg). The obtained (3-{2-[4-(2,4-dimethylphenyl)piperazine-1-carbonyl]-5-(1,1-dioxo-1λ6-isothiazolidin-2-yl)phenoxy}propyl)carbamic acid tert-butyl ester (221 mg) was dissolved in dichloromethane (2 mL), trifluoroacetic acid (0.46 mL) was added, and the mixture was stirred at room temperature overnight. The reaction mixture was poured into ice water, the mixture was neutralized with sodium hydrogen carbonate and extracted with chloroform, and the solvent was evaporated. The obtained residue was purified by NH-coated silica gel column chromatography (ethyl acetate:methanol) to give the title compound (74 mg).

Provenance & Evidence