反应详情

2-(2-Hydroxy-5-methoxybenzylamino)thiophene (2.3 g) was dissolved in 25 ml of methylene chloride under nitrogen atmosphere and 1.44 g (5 mmole) of solid naphthalene 1,5-disulfonic acid was added. The solid acid dissolved quickly and a white precipitate appeared after 5 minutes of vigorous stirring. After the reaction mixture was stirred 1/2 hour the resultant precipitate was collected, washed 2×10 ml with methylene chloride and air-dried to give 3.6 g of 2-(2-hydroxy-5-methoxybenzylamino)thiophene naphthalene-1,5-disulfonic acid salt (m.p. 185 dec).

1. dissolutionThe solid acid dissolved quickly
2. customwas collected
3. washwashed 2×10 ml with methylene chloride
4. customair-dried