p-Toluenesulfonic acid → 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethylquinazolin-4(3H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-amino-4,6-dimethylbenzamide (0.2 g, 1.22 mmol), 4-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-3,5-dimethyl-benzaldehyde (0.376 g, 1.22 mmol), sodium hydrogensulfite (0.22 g, 1.22 mmol) and p-toluenesulfonic acid (0.116 g, 0.61 mmol) in N,N-dimethyl acetamide (10 mL) was stirred at 155° C. for 14 h. The reaction mixture was cooled to room temperature and diluted with water (50 mL). The solid crashed out and was collected by filtration to afford impure product. The solid was re-dissolved in THF (30 mL) and mixed with TBAF in THF (5 mL, 5 mmol). The reaction mixture was stirred at room temperature for 14 h and concentrated using a rotary evaporator to afford an oily residue. Further purification by column (SiO2, EtOAc/DCM/MeOH=12:4:1) yielded an off-white solid. This solid was diluted with MeOH (10 mL) to make a slurry. The solid was collected by filtration and washed with MeOH to afford 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethylquinazolin-4(3H)-one (98 mg, 24%) as a white solid. Selected data: MS (ES) m/z: 339.10; MP 259.6-261.2° C.

Provenance & Evidence