3-Cyclobutene-1,2-dione, 3,4-dimethoxy- → HCID 21423019, compound
Reaction equation
[CH3:1][CH:2]1[CH2:7][NH:6][CH2:5][CH:4]([CH3:8])[N:3]1[CH2:9][CH2:10][CH3:11].CO[C:14]1[C:15](=O)[C:16](=[O:20])[C:17]=1[O:18]C>CO>[CH3:8][CH:4]1[N:3]([CH2:9][CH2:10][CH3:11])[CH:2]([CH3:1])[CH2:7][N:6]([C:14]2[C:17](=[O:18])[C:16](=[O:20])[C:15]=2[N:6]2[CH2:5][CH:4]([CH3:8])[N:3]([CH2:9][CH2:10][CH3:11])[CH:2]([CH3:1])[CH2:7]2)[CH2:5]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 1.5 grams of 2,6-dimethyl-1-propylpiperazine in 10 ml. of methanol is mixed with a solution of 3,4-dimethoxy-3-cyclobutene-1,2-dione in 25 ml. of methanol and refluxed for 5 hours. The solvent is then evaporated by heating on a steam bath and the resulting red semi-crystalline residue is triturated with anhydrous ethyl ether and filtered and the filter cake is washed with 5 ml. of anhydrous ethyl ether to remove the colored by-products and leave 3,4-bis(3,5-dimethyl-4-propyl-1-piperazinyl)-3-cyclobutene-1,2-dione as a grey-white crystalline solid melting at about 145°-147° C.