2-(4-Oxo-2-thioxo-thiazolidin-3-ylamino)-benzoic acid → 2-{5-[1-[5-(4-Tert-butyl-phenyl)-furan-2-yl]-meth-(e)-ylidene]-4-oxo-2-thioxo-thiazolidin-3-ylamino}-benzoic acid

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Reaction Steps

A mixture of 2-(4-oxo-2-thioxo-thiazolidin-3-ylamino)-benzoic acid (0.090 g, 0.34 mmol), 5-(4-tert-butyl-phenyl)-furan-2-carbaldehyde (0.082 g, 0.36 mmol) and ethylenediamine diacetate (0.065 g, 0.036 mmol) in methanol (8 mL) was stirred at room temperature for 17 h. The reaction mixture was poured into stirred 0.6 N aq sodium hydrogensulfite (50 mL). The mixture was vigorously stirred for 15 min. The solid product was filtered off and washed on funnel successively with 0.6 N aq sodium hydrogensulfite (2 mL), water (2×2 mL), ether (2 mL) and hexanes (2 mL). The material was dried in a vacuum oven at 65° C. for 19 h to afford 2-{5-[1-[5-(4-tert-Butyl-phenyl)-furan-2-yl]-meth-(E)-ylidene]-4-oxo-2-thioxo-thiazolidin-3-ylamino}-benzoic acid (140 mg, 87%) as a solid. 1H NMR (400 MHz, DMSO-d6): δ 1.32 (9H, s), 6.45 (1H, m), 6.82 (1H, m), 7.23 (1H, m), 7.30 (1H, d, J=3.6), 7.40 (1H, d, J=3.6), 7.61 (2H, m), 7.74 (1H, s), 7.82 (2H, m), 7.91 (1H, m), 11.20 (1H, bs). LC/MS APCI 477.9, HPLC 91.0%

Provenance & Evidence