Sodium Hydroxide → (8,9-Dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)acetic acid sodium salt hydrate

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Reaction Steps

An ethanolic (86 mL) solution of (8,9-dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)acetic acid 1,1-dimethylethyl ester (2.29 g, 8.60 mmol) was treated at room temperature with 2.5N sodium hydroxide solution (3.5 mL, 8.7 mmol) and left stirring overnight. The suspension was filtered, washing with ethyl acetate to give a solid which was recrystallized from methanol/water/isopropanol (final volume 50 mL) to afford (8,9-dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)acetic acid sodium salt hydrate (1.43 g, 66%, mp 280°-300° C. dec); MS (-FAB): 231 (M-H, 37), 209 (M-Na, 100); 1H NMR (DMSO 1 drop of DCl, 400 MHz): δ 4.40 (s, 2H), 3.36-3.25 (m, 4H), 1.89 (m, 2H).

Provenance & Evidence