Potassium Carbonate → Ethyl [(2-(2,2-diphenylethyl)thio-4,5-dihydronaphtho[1,2-d]thiazol-6-yl)oxy]acetate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl[(2-mercapto-4,5-dihydronaphtho[1,2-d]thiazol-6-yl)oxy]acetate (1.80 g, 5.60 mmol) in N,N-dimethylformamide (15 mL) was added 2,2-diphenylethyl methanesulfonate (1.80 g, 6.20 mmol) followed by addition of potassium carbonate (857 mg, 6.20 mmol), and the mixture was stirred at 60° C. for 2 hours. This reaction mixture was diluted with water and extracted with ethyl acetate. The organic layer was washed with water and saturated aqueous sodium chloride solution, dried over MgSO4, and filtered. The filtrate was concentrated under reduced pressure to provide 2.70 g of ethyl[[2-(2,2-diphenylethyl)thio-4,5-dihydronaphtho[1,2-d]thiazol-6-yl]oxy]acetate. To a solution of this compound (2.00 g, 3.99 mmol) in ethanol (8 mL)-water (2 mL) was added sodium periodate (4.30 g, 19.9 mmol) and the mixture was refluxed for 14 hours. This reaction mixture was diluted with ethyl acetate and water and, after phase separation, the aqueous layer was extracted with ethyl acetate. The pooled organic solution was washed with water, dried over MgSO4, and filtered and the filtrate was concentrated under reduced pressure. To a solution of the above concentration residue in tetrahydrofuran (16 mL)-methanol (4 mL) was added 1N-aqueous sodium hydroxide solution (2 mL) dropwise, and the mixture was stirred at room temperature for 10 minutes. The solvent was then distilled off under reduced pressure. To the residue was added 1N-hydrochloric acid, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated aqueous sodium chloride solution, dried over MgSO4, and filtered and the filtrate was concentrated under reduced pressure. The residue was recrystallized from ethyl acetate-hexane to provide 0.72 g of the title compound. Yield 41%.

Provenance & Evidence