4-[(4-Bromo-3,4,4-trifluorobutyl)thio]-6-(2,2,2-trifluoroethoxy)-pyrimidin → 4-[(4,4-Difluoro-3-butenyl)thio]-6-(2,2,2-trifluoroethoxy)-pyrimidine

Participants

Reaction Steps

The product from step 1 (2.8 g) was treated with zinc powder (1.376 g) in methanol (100 cm3) containing zinc iodide (catalytic amount). The mixture was heated under reflux for 7 hours and glc then indicated that only about 70% conversion had occurred. A further 0.459 g of zinc powder was added and heating continued for 6 hours. The cooled reaction mixture was filtered through a plug of celite, which was washed with more ethanol. The combined organic solutions were evaporated under reduced pressure to give a yellow oil. Purification by chromatography on silica gel, eluting with 1:10 ethyl acetate:hexane gave Compound No. 13 (1.1 g). M+ =300; 1H NMR (CDCl3): δ2.4(2H,m); 3.2(2H,t); 4.2-4.35(1H,m); 4.78(2H,q); 6.7(1H,s); 8.55(1H,s); (oil).

Provenance & Evidence