反应详情

A solution of trimethylsilylethanol (10 g, 85 mmol) in 30 mL anhydrous THF was cooled to -68° C. in a dry ice/isopropanol bath. A solution of n-butyl lithium (33.8 mL, 2.5M in THF) was added dropwise over 15 min. The solution was stirred for 10 min at this temperature and then added to a solution of 2,4-dichloropyrimidine (12.62 g. 85 mmol) in 75 mL THF at -35 to -25° C. The final yellowish solution was allowed to come to room temperature under an argon atmosphere then stirred at this temperature for 1 hr. This solution was diluted with 200 mL of diethylether and washed with cold water (100 mL), saturated NaHCO3 (100 mL) and brine, then dried over MgSO4, filtered and evaporated to yield a tan syrup. This syrup may be crystallized from hexanes at -60° C. to yield 12 as a light yellow solid, 17.8 g (91%) . 1H-NMR (CDCl3): δ 8.36 (d, 1 H, H-6); 6.93 (d, 1 H, 5-H); 4.43 and 1.17 (t,t; 4 H; CH2CH2) 1.06 (bs, 9 H. TMS).

1. customto come to room temperature under an argon atmosphere
2. stirringthen stirred at this temperature for 1 hr
3. washwashed with cold water (100 mL), saturated NaHCO3 (100 mL) and brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. customevaporated
7. customto yield a tan syrup
8. customThis syrup may be crystallized from hexanes at -60° C.