HCID 11124297, compound → HCID 69820135, compound

Participants

Reaction Conditions

Reaction Steps

To tetrahydrofuran (30 mL) was added (6-bromo-4-ethyl-benzo[1,3]dioxole) (1.24 g, 5.41 mmol). After cooling to −78° C., a solution of n-butyllithium (1.6 M in hexane, 3.54 mL) was added. After stirring for 45 minutes, a solution of anhydrous zinc bromide (1.27 g, 5.69 mmol) in tetrahydrofuran (20 mL) was added, and the mixture was stirred at −72° C. for 45 minutes, followed by warming to −25° C. To this mixture was added 1,1-dioxo-4-(trifluoro-methanesulfonyloxy)-2-(2-trifluoromethyl-phenyl)-1,2-dihydro-1λ6-benzo[e][1,2]thiazine-3-carboxylic acid methyl ester (1.49 g, 2.80 mmol), and palladium tetrakis(triphenyl phosphine) (1.30 g, 1.05 mmol). The mixture was heated to 70° C. for 2.5 hours and was evaporated in vacuo to an oil. The mixture was resuspended in ethyl acetate, washed with 1N citric acid solution, brine, filtered, and dried over anhydrous magnesium sulfate. The suspension was filtered and stripped to an oil which was partially crystallized from ethyl ether giving a solid. The filtrate was concentrated in vacuo and was chromatographed on 50 g silica gel eluted with a mixture of ethyl acetate and hexane (30:70). The appropriate fractions were concentrated in vacuo and crystallized from ethyl ether. These solids were combined with those recovered from the initial crystallization and were dried in vacuo giving a solid, 0.836 g, 53% yield. NMR spectra and elemental analysis were consistent with the structure.

Provenance & Evidence