| 摘要 |
NEW MATERIAL:A compound expressed by formula I (R1 and R2 are 1-4C alkyl; X is Cl or OH). USE:A synthetic raw material for squarylium compounds. PREPARATION:3,4-Dichloro-3-cyclobutene-1,2-dione expressed by formula Il is reacted with a 3,5-difluoroaniline derivative expressed by formula III in a solvent, such as CCl4 or acetonitrile, as desired, in the presence of a catalyst, such as AlCl3, at 0-40 deg.C to provide a chlorocyclobutenedione derivative, which, as desired, is hydrolyzed to afford the aimed compound expressed by formula I (X is OH). |
