1-Methylpiperazine → HCID 85916567, compound

Participants

Reaction Steps

3.5 g of 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo-[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester (0.01 mol) are dissolved in 20 ml of butanol. 2 g of N-methylpiperazine are added and the solution is refluxed with stirring for 12 hours. After evaporation of the solvent, the residue is extracted three times with 50 ml portions of ethyl acetate. The ethyl acetate is distilled off until the volume is about 30 ml. The 8-ethyl-5-(4-methyl-1-piperazinyl)-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester crystallizes, yield 3.1 g (76%); m.p. 111°-113° (ethyl acetate).

Provenance & Evidence