p-Toluenesulfonic acid → (E)-2-(3-bromo-5-(trifluoromethoxy)benzylidene)-6-methoxy-5-morpholino-2,3-dihydro-1H-inden-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of compound 13 (150 mg, 0.607 mmol) in toluene 15 mL was added 3-bromo-5-(trifluoromethoxy)benzaldehyde 29 (115.4 mg, 0.607 mmol). PTSA (230.9 mg, 1.214 mmol) was added to the reaction mixture, then stirred at 120° C. for 6 h. The reaction mixture was diluted with ethyl acetate and washed with water (3×25 mL). The organic layer was dried over sodium sulphate and concentrated to get the crude compound (E)-2-(3-bromo-5-(trifluoromethoxy)benzylidene)-6-methoxy-5-morpholino-2, 3-dihydro-1H-inden-1-one 30, which was purified through flash chromatography by using 100-200 mesh silica gel. Compound 30 was eluted at 25% ethyl acetate in hexane to afford a yellow coloured solid. To 30 (45 mg, 0.107 mmol), dissolved in methanol 20 mL, was added Pd/C 20 mg and stirred under hydrogen balloon for 6 h. The reaction was filtered through celite bed and washed with excess methanol. The organic layer was concentrated to get the crude des-brominated compound 31. The crude 31 was purified by flash chromatography using 100-200 mesh silica gel. Compound 31 was eluted as des-brominated compound at 25% ethyl acetate in hexane as half white coloured solid compound 6-methoxy-5-morpholino-2-(3-(trifluoromethoxy)benzyl)-2,3-dihydro-1H-inden-1-one 31. 1HNMR (400 MHz, CDCl3) δ ppm 7.43 (m, 4H), 7.18 (s, 1H), 6.81 (s, 1H), 3.89 (m, 3H), 3.87 (m, 4H), 3.43 (m, 1H), 3.17 (m, 4H), 3.06 (m, 1H), 2.97 (m, 1H), 2.69 (m, 2H); MS (ESI) m/z 422.1 (M+H).

Provenance & Evidence