Cell differentiation enhancement by hydrophilic derivatives of 4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-diones in HL-60 leukemia cells.

N-(2-dimethylaminoethyl)-4,8-dihydrobenzo[1,2-b:5,4-b′]-dithiophene-4,8- dione-2-carboxamide (13) and 2-(1-hydroxyethyl)-4,8-dihydrobenzo[1,2-b:5,4-b′]dithiophene-4,8-dione (18) were found to exhibit excellent differentiation effects on HL-60 cells. To improve the water solubility of compound 18, its ester-type hydrophilic prodrugs (23-26) was synthesized.