Water → HCID 57738877, compound

Participants

Reaction Steps

To a 100-mL round-bottom flask was added diethyl 7-(2-ethoxy-2-oxoethyl)-2,3,4,7-tetrahydro-[1,4]dioxepino[2,3-c]pyrrole-6,8-dicarboxylate (17.56 g, 47.5 mmol), DI water (45 mL), acetone (25 mL), and potassium hydroxide (13.34 g, 238 mmol). The reaction mixture was bubbled with argon for 20 minutes, then refluxed for 2.5 hours, resulting in a deep brown solution. The organic volatiles were removed in vacuo and the remaining aqueous layer was chilled in an ice bath. To the mixture was added concentrated sulfuric acid until a pH of 6 was reached, whereupon a white solid precipitate formed. This precipitate was filtered from the red aqueous solution and washed with several portions of DI water, and after drying weighed 13.55 g (100%). To confirm the structure NMR analysis was performed on the fully deprotonated version by dissolving into a NaOD/D2O solution. 1H NMR (300 MHz, D2O/NaOD): δ 5.17 (s, 2H), 4.13-4.09 (m, 4H), 2.19 (p, 2H, J=5.7 Hz). 13C NMR (75 MHz, CDCl3): δ 180.9, 171.0, 141.9, 120.3, 74, 9, 51.9, 36.3. The product was used in the subsequent reaction without further purification.

Provenance & Evidence