p-Toluenesulfonic acid → HCID 57628288, compound

Participants

Reaction Steps

Into a solution obtained by dissolving 3-aminothiophene (2.5 g, 25.2 mmol) in toluene (85.0 g), which was obtained by the method in Example 1 using methyl 3-aminothiophene-2-carboxylate as a starting material were added p-toluenesulfonic acid (0.2 g, 1.1 mmol) and 4-methyl-2-pentanone (100.0 g, 998.4 mmol) at room temperature, and the resulting solution was stirred under reflux under nitrogen atmosphere for 2 hours. The reaction solution was cooled to room temperature, and then washed with a 10% aqueous sodium hydroxide solution two times, and the obtained organic layer was concentrated under reduced pressure to give an oily substance. The resulting concentrate was purified by silica gel column chromatography to give 0.9 g of an oily substance as a mixture of three compounds including 3-amino-2-{(E)-(4-methyl-2-penten-2-yl)}thiophene, 3-amino-2-{(Z)-(4-methyl-2-penten-2-yl)}thiophene and 3-amino-2-(4-methyl-1-penten-2-yl)thiophene (yield: 19%).

Provenance & Evidence