反应详情

A solution of cyclopropyl urea (10 g, 100 mmol, 1 eq) and ethyl 3-amino-3-ethoxy-acrylate HCl (19.55 g, 100 mmol, 1 eq) in Ethanol (125 ml) was heated at 75° C. for 2 hours. To this solution was added 2 equivalents of NaOEt then heated for an additional one hour. Solvent was evaporated, water (50 ml) was added then acidified via concentrated HCl to pH of 4-5. The resulting precipitate was obtained by filtration and washed with cold water to give the desired product (9.35 g, 56%) after vacuum dried overnight at 40° C.: The desired isomer was determined via 2D-NMR; 1H NMR (400 MHz, DMSO-d6) δ 10.18 (1H), 6.10 (2H), 4.44 (1H), 2.38 (1H), 0.85 (2H), 0.62 (2H); m/z (ES+) 168.17

1. temperaturethen heated for an additional one hour
2. customSolvent was evaporated
3. additionwater (50 ml) was added
4. customThe resulting precipitate was obtained by filtration
5. washwashed with cold water