Methane → N'-[2,3-bis(4-methyl-1-piperazinyl)-6-quinoxalinyl]-N,N-dimethylpropionamidine

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Reaction Steps

To a solution of 11.33 g. (0.112 mole) of N,N-dimethylpropionamide in 110 ml. of acetonitrile (dried over molecular sieves) is added 8.3 ml. of phosphorous oxychloride at 5°-10° C. The mixture is stirred at room temperature for 90 minutes. To the resulting yellow solution is added 13.7 g. (0.040 mole) of 6-amino-2,3-bis(4-methyl-1-piperazinyl)quinoxaline (prepared as in Example 1) in several portions with stirring. The mixture is placed in an oil bath at 65° C. and stirred for 16 hours. The reaction mixture is cooled and is poured into 400 ml. of ice plus water, stirred for 10 minutes and filtered. The filtrate is made alkaline to a pH greater than 13 with 5 N sodium hydroxide and extracted with five 100 ml. portions of chloroform. The combined extract is washed with two 100 ml. portions of water, dried over anhydrous potassium carbonate and anhydrous calcium sulfate and stripped of solvent by water pump evacuation to yield a residual oil which is crystallized on standing. The residue formed is recrystallized from 350 ml. of acetonitrile and is filtered and the solid collected is dried in vacuo at 78° C. over phosphorous pentoxide. The yellow solid obtained is dissolved in 160 ml. of hot acetonitrile, treated with activated charcoal, recrystallized by cooling at -10° C. and is filtered and dried as above to give 4.0 g. of yellow solid, m.p. 173°-175° C.

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