反应详情

A mixture of 5-methyl-4-amino-thiophene-2-carboxylic acid (1,3-benzodioxol-5-ylmethyl)-amide from Step 2 (0.6 g, 2.1 mmol) and benzyl isocyanate (0.28 g, 2.1 mmol) in 1,4-dioxane (100 mL) was stirred under an inert atmosphere and heated to reflux. After 30 minutes, the mixture was allowed to cool, and the solvent was removed under reduced pressure. The residue was triturated in a small amount of acetonitrile, cooled, and filtered to afford 0.33 g of 4-(3-benzyl-ureido)-5-methyl-thiophene-2-carboxylic acid (1,3-benzodioxol-5-ylmethyl)-amide. A sample was recrystallized from methanol to give product with a mp 194-195° C.

1. temperatureheated to reflux
2. temperatureto cool
3. customthe solvent was removed under reduced pressure
4. customThe residue was triturated in a small amount of acetonitrile
5. temperaturecooled
6. filtrationfiltered