Phosphorus oxychloride → 2,3-Dichloro-5-iodopyridine

Temperature

130 °C

A 100 ml 3-necked round bottom flask, fitted with a condenser topped with a N2 inlet, a mechanical stirrer and a thermometer, was charged with 17.2 g (0.0673 mole) of 3-chloro-2-hydroxy-5-iodopyridine, 14.85 g (0.0713 mole) of PCl5, and 1 ml (1.68 g; 0.0109 mole) of POCl3. The reaction mixture, containing solids, was slowly stirred and slowly heated to 130° C. The reaction mixture was stirred under N2 for 5 hours after which it was cooled to room temperature and allowed to stand overnight. The reaction mixture was cautiously poured into crushed ice and allowed to stand for 1 hour. Methylene chloride (200 ml) was added to the reaction mixture to dissolve the solids present in it. The layers was separated and the organic phase was washed with dilute base, water and saturated NaCl. After drying over anhydrous MgSO4 and filtration, the solvent was evaporated leaving 11.8 g of a yellow solid. The solid was recrystallized from methanol resulting in 6.60 g of solid that had spectral and physical properties identical to the product obtained in Example 1, STEP D.

1. customA 100 ml 3-necked round bottom flask, fitted with a condenser
2. customtopped with a N2 inlet, a mechanical stirrer
3. additionThe reaction mixture, containing solids
4. stirringThe reaction mixture was stirred under N2 for 5 hours after which it
5. temperaturewas cooled to room temperature
6. additionThe reaction mixture was cautiously poured
7. custominto crushed ice
8. waitto stand for 1 hour
9. dissolutionto dissolve the solids present in it
10. customThe layers was separated
11. washthe organic phase was washed
12. additionwith dilute base, water and saturated NaCl
13. dry with materialAfter drying over anhydrous MgSO4 and filtration
14. customthe solvent was evaporated

ORD record

ord-082aafd763bd47a08e2e03f7ceada57f

Source dataset

uspto-grants-1985_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04517368