Reaktion #336977

Reaktionsgleichung

2,6-dichloropurine

dihydropyran

D-(+)-10-camphorsulfonic acid

→

desired product

2,6-dichloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purine

Lösungsmittel

1,2-dichloroethane

CCl3H

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITThe initially white suspension, after 2 hrs
2. 2
   Waschenwashed with brine
3. 3
   TrocknenThe organic layer is dried over MgSO4
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated
6. 6
   Sonstigetriturated with hexane 3 times

Vorschrift

A suspension of 2,6-dichloropurine (22.0 g, 116.4 mmol), dihydropyran (11.5 mL, 126 mmol) and D-(+)-10-camphorsulfonic acid (2.20 g, 9.47 mmol) in 1,2-dichloroethane (300 mL) was stirred at 83° C. for 16 hours. The initially white suspension, after 2 hrs, turned yellow and then black. The reaction mixture was diluted with CCl3H and then washed with brine. The organic layer is dried over MgSO4, filtered, concentrated and triturated with hexane 3 times to give the desired product. 1HNMR (300 MHz, CCl3D): δ 8.33 (s, 1H), 5.75 (dd, J=10.4 Hz, 2.5 Hz, 1H), 4.18 (m, 2H), 3.79 (m, 2H), 1.84 (m, 4H).

Quelle