Acetic Anhydride → HCID 13911281, compound
Reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[N:9]1[CH2:14][CH2:13][N:12]([CH2:15][CH2:16][N:17]2[C:22](=[O:23])[C:21]3[S:24][CH:25]=[CH:26][C:20]=3[NH:19][C:18]2=[O:27])[CH2:11][CH2:10]1.[C:28](OC(=O)C)(=[O:30])[CH3:29]>>[C:28]([N:19]1[C:20]2[CH:26]=[CH:25][S:24][C:21]=2[C:22](=[O:23])[N:17]([CH2:16][CH2:15][N:12]2[CH2:11][CH2:10][N:9]([C:4]3[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=3[O:2][CH3:1])[CH2:14][CH2:13]2)[C:18]1=[O:27])(=[O:30])[CH3:29]Participants
3
Procedure
A solution of 3-[2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl]thieno[3,2-d]pyrimidine-2,4-dione (2.6 g, 6.73 mmol) in acetic anhydride (30 ml) was heated to reflux for 5 hours. Acetic anhydride was removed in vacuo. The residue was dissolved in toluene, and the toluene was removed in vacuo. This process was repeated twice to remove any residual acetic anhydride. The residue was purified by flash chromatography on silica gel 60 (60 g) using 2.5% methanol in methylene chloride as eluant to give the product (1.65 g, 57% yield) as an off-white solid, mp 156°-158° C.