Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)- → HCID 21196718, compound

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Reaction Steps

A 4.20 g of sodium periodate was added gradually to a mixture of 1.80 g of 5-allyl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene, 25 mg of osmium tetraoxide, 15 ml of water and 45 ml of dioxane, while keeping the reaction mixture at 24 to 26° C., and then the mixture was stirred at room temperature for 3 hours. After extraction of the reaction mixture with ethyl acetate, the organic layers were combined, washed with 2% sodium thiosulfate aqueous solution, water and brine in that order and then dried with anhydrous magnesium sulfate. After removal of the drying agent, the solvent was concentrated under a reduced pressure, and the resulting residue was purified by a silica gel column chromatography to give 1.33 g of (4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophen-5-yl)acetaldehyde. A 1.32 g of the aldehyde compound and 1.39 g of N-acetylethylenediamine were dissolved in 50 ml of toluene. Then, 10 mg of camphorsulfonic acid was added, and the mixture was heated under reflux for 3 hours while removing the produced water. After cooling, the reaction solution was poured into ice-cooled saturated sodium bicarbonate aqueous solution and extracted with ethyl acetate. The organic layers were combined, the drying agent was removed by filtration and then the solvent was concentrated under a reduced pressure to give 1.38 g of N-(2-(4,5-dihydro-1H-thieno[2,3-g]indol-1-yl)ethyl]acetaamide. From this compound, N-[2-(1H-thieno[2,3-g]indol-1-yl)ethyl]acetamide was obtained in the similar manner as described in Reference Example 60.

Provenance & Evidence