4-Methylmorpholine → N-[(2E)-2-hydroxyimino-2-[3-[(2-methylpropan-2-yl)oxy]propanoylamino]-1-phenylethyl]-3-(4-phenylphenyl)sulfonyl-1,3-thiazolidine-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

Carboxylic acid, e.g., 3-tert-butoxypropionic acid (35 mg, 0.24 mmol), was dissolved in THF (2 mL). The resulting solution was cooled down to −15° C. NMM (84 μL, 0.76 mmol), followed by isobutyl chloroformate (33 μL, 0.25 mmol), were added. The mixture was stirred at −15° C. for 30 min. Intermediate Id, e.g. N-[(1R,2Z)-2-amino-2-(hydroxyimino)-1-phenylethyl]-3-(biphenyl-4-ylsulfonyl)-1,3-thiazolidine-2-carboxamide (108 mg, 0.22 mmol) in THF (2 mL) was added dropwise. The mixture was stirred overnight, letting the temperature increasing up to RT. Solvents were evaporated. The resulting oil was dissolved in AcOEt, and washed with sat NH4Cl and sat NaHCO3. Aqueous phases were extracted with two portions of AcOEt. Combined organic phases were dried over MgSO4, filtrated and evaporated, affording intermediate Id′, e.g. 3-(biphenyl-4-ylsulfonyl)-N-[(2E)-2-[(3-tert-butoxypropanoyl)amino]-2-(hydroxyimino)-1-phenylethyl]-1,3-thiazolidine-2-carboxamide (118 mg, 86% yield), which was directly used in the next step.

Provenance & Evidence