Potassium Carbonate → 3-Phenyl-1-oxa-2,4-diaza-spiro[4.4]non-2-en4-ylamine

Participants

Reaction Steps

A round bottom flask was charged with a solution of 20 g of K2CO3 in 50 mL of water and cooled in an ice bath. Cyclopentylidene-hydrazine (7.9 g, 80 mmol) in 25 mL of CH2Cl2 was added, followed by a drop-wise addition of benzohydroximoyl chloride (5 g, 0.032 mmol) in 25 mL of CH2Cl2 over a period of 15 minutes. The mixture was stirred for several days, and allowed to warm to room temperature. Water (50 mL) and CH2Cl2 (50 mL) were added and the phases were separated. The organic layer was washed twice with 50 mL of water, dried over MgSO4, and filtered. The solvent was removed in vacuo, leaving 9 g of a waxy solid. Crystallization from ethyl acetate/hexane provided 3.5 g (50%) of 3-phenyl-1-oxa-2,4-diaza-spiro[4.4]non-2-en-4-ylamine after drying. 1H-NMR (300 MHz, CDCl3) δ (ppm): 7.72 ((m, 2H), 7.46 (m, 3H), 3.54 (s, 2H), 2.1 (m, 2H), 2.0 (m, 2H), 1.85 (m, 2H), 1.8 (m, 2H).

Provenance & Evidence