反应详情

20.2 g. of 2,4-dichloropyridin-5-methanol (0.11 mol.) and 150 ml. of phosphorus oxychloride are refluxed for 19 hours. Then the excess phosphorus oxychloride is removed in vacuo and ice is added to the residue. 5-Chloromethyl-2,4-dichloropyridine is filtered off, washed with water, dried in the desiccator over P2O5 and recrystallized from hexane; yield 17.95 g. (83%), m.p. 55°-56°.

1. customThen the excess phosphorus oxychloride is removed in vacuo and ice
2. additionis added to the residue
3. filtration5-Chloromethyl-2,4-dichloropyridine is filtered off
4. washwashed with water
5. dry with materialdried in the desiccator over P2O5
6. customrecrystallized from hexane