Pyrimidine,4-methyl-2-(1-piperazinyl)-(9CI)

110-85-0

13036-57-2

59215-36-0

GENERAL METHOD: 2-Chloro-4,6-disubstituted pyrimidines were prepared by reacting the diazonium salt of 4,6-disubstituted pyrimidin-2-amines with concentrated hydrochloric acid and zinc chloride. In the reference, 23 compounds were synthesized by improving the method. The procedure was as follows: 2-chloro-4-methylpyrimidine (18 mmol) was added batchwise to a stirred solution of piperazine (45 mmol) and potassium carbonate (16.5 mmol) in water (20 mL) at 50-60 °C. The reaction mixture was stirred at 60-65 °C for 1 h and subsequently cooled to room temperature. The resulting yellow solid 1,4-bis(4,6-disubstituted pyrimidin-2-yl)piperazine was collected by filtration. The filtrate was extracted three times with chloroform, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford the target product 4-methyl-2-(1-piperazinyl)pyrimidine, which could be used in the subsequent reaction without further purification. Product 3a is a yellow solid with 81% yield and 45-48°C melting point; product 3b is a yellow solid with 79% yield and 82-84°C melting point.