1,1'-Carbonyldiimidazole → N-(4-iso-propylbenzenesulfonyl)-alpha-(4-(sulfamylcarbamyl)-2-n-propylphenoxy)-3,4-methylenedioxyphenylacetamide

Participants

Reaction Steps

A solution of 158 mg (0.293 mmol) of N-(4-iso-propylbenzenesulfonyl)-α-(4-carboxy-2-n-propylphenoxy)-3,4-methylenedioxyphenylacetamide (free acid form of the product of Example 58) and 71 mg (0.440 mmol) of 1,1'-carbonyldiimidazole in 1 mL of dry tetrahydrofuran was refluxed for 3.5 hours. The reaction mixture was cooled to room temperature and 141 mg (1.47 mmol) of sulfamide and 110 μL (0.733 mmol) of DBU were added and the mixture was refluxed again. The reaction progress was monitored by analytical HPLC analysis using a Waters 600E HPLC system with a 4.6×250 mm 5 μM Zorbax-RX C8 at 40° C. and eluting isocratically 1.5 mL/min using 60% A (95-5 acetonitrile-water) 40% B (95-5 water-acetonitrile) each with 0.1% TFA where the column effluent was monitored at 254 nM with a Waters model 490 UV-visible detector. After 2.0 hour of additional refluxing, analytical HPLC analysis indicated that the coupling was complete. The reaction mixture was diluted with 2.5 mL of methanol and 2 mL of water, filtered and the filtrate partially purified was purified using a Varian 5500 HPLC by applying the compound in a 4.5 mL total volume (2.5 mL methanol and 2 mL water) onto two in series 21.2×250 mm Zorbax ODS C18 columns and eluting at 15 mL/min with 60% acetonitrile and 40% water both with 0.1% TFA. The column effluent was monitored 254 nM with a Kratos Spectroflow 783 UV detector. Combination and evaporation of the purified fractions afforded 50 mg (28%) of the title compound. The mixed fractions were combined and subjected to a second preparative HPLC chromatography using a linear gradient over 35 minutes from 65% water and 35% acetonitrile both with 0.1% TFA to 65% acetonitrile and 35% water both with 0.1% TFA, holding all other conditions from the previous chromatography. The purified fractions were combined and concentrated to afford 57 mg (31%) of the title compound, which was combined with the previously purified material to provide a total of 107 mg (59%) of the title compound as an amorphous solid.

Provenance & Evidence