Piperazine → HCID 20086571, compound

Reaction equation

[C:1]([O:4][C:5]1[C:6]([CH3:21])=[C:7]([CH3:20])[C:8]2[O:13][C:12]([CH3:17])([C:14]([OH:16])=O)[CH2:11][CH2:10][C:9]=2[C:18]=1[CH3:19])(=[O:3])[CH3:2].[C:22]([N:29]1[CH:33]=[CH:32][N:31]=[CH:30]1)(N1C=CN=C1)=O.N1CCNCC1>ClC(Cl)C>[C:1]([O:4][C:5]1[C:6]([CH3:21])=[C:7]([CH3:20])[C:8]2[O:13][C:12]([C:14]([N:29]3[CH2:33][CH2:32][NH:31][CH2:30][CH2:22]3)=[O:16])([CH3:17])[CH2:11][CH2:10][C:9]=2[C:18]=1[CH3:19])(=[O:3])[CH3:2]

Participants

Procedure

2.7 g (0.009 mol) of 3,4-dihydro-6-acetoxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carboxylic acid are dissolved in 200 cm3 of anhydrous dichloroethane. 1 eq of carbonyldiimidazole (0.009 mol), i.e. 1.5 g, is added. The mixture is left to stir for 1 h and then 7.5 g of piperazine (0.009 mol) dissolved in 200 cm3 of dichloroethane are added. The oil obtained after evaporation is purified on a silica column by eluting with a CH2Cl2 /ethanol/NH4OH (88/10/2) mixture and crystallized from isopropyl ether.