2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2,4-Dichloro-6-[3-(trimethylsilyl) propyl]pyrimidine

Participants

Reaction Conditions

Reaction Steps

At −20° C. to a solution of Li (3 gram) in diethyl ether (150 ml) was slowly added 3-trimethylsilyl-propyl bromide (33.8 gram). Stirred for 30 min at −20° C. and 1 hour at 0° C. This solution was slowly added to a solution of 2,4 dichloro pyrimidine (19.3 gram) in diethyl ether (388 ml) at −30° C. stirred for 30 min at −30° C. and 30 mm at 0° C. to this solution was added glacial acid (11.1 ml), H2O (1.15 ml) in THF (34.7 ml) and DDQ (29.7 gram) in THF (127 ml). Reaction mixture was stirred for 30 min. At 0° C. NaOH (3 m, 50 ml) and Na2S2O3 (saturated solution, 200 ml) was added. The reaction mixture was stirred for 30 min and extracted two times with diethyl ether. The diethyl ether layers were combined, washed with brine, dried over magnesium sulfate, filtered, and the solvents were removed in vacuo. Silica gel chromatography (heptane/ethyl acetate 4/1) provided 23.6 g of 2,4-dichloro-6-[3-(trimethylsilyl) propyl]pyrimidine.

Provenance & Evidence