反应详情

To a solution of sodium ethylate (75 parts by weight) in anhydrous ethanol (500 parts by volume), guanidine monohydrochloride (96 parts by weight) is added under stirring and ice-cooling to make an ethanolic solution of free guanidine. To this solution, a solution of ethyl 5-methylisoxazole-3-carboxylate (155 parts by weight) in anhydrous ethanol (200 parts by volume) is added within 2 hours under stirring at 40° C. The resultant mixture is allowed to stand at 20° C for 12 hours. The precipitated crude crystals are filtered off, washed with a small amount of water and recrystallized from ethanol to give 1-(5-methyl-3-isoxazolylcarbonyl)guanidine as colorless prisms melting at 192° to 192.5° C under decomposition. IR (Nujol): 1652 cm-1 (=C=O).

1. temperatureice-cooling
2. stirringunder stirring at 40° C
3. customThe precipitated crude crystals
4. filtrationare filtered off
5. washwashed with a small amount of water
6. customrecrystallized from ethanol