Hydrochloric Acid → 5-[[3,5-Bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-(ethylmethylamino)-4-thiazolidinone

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Reaction Conditions

Reaction Steps

7.02 g of 5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-(ethylmethylamino)-2-thioxo-4-thiazolidinone (from Example 40D) and 86.3 ml of toluene were stirred and heated to 60° C. under a nitrogen atmosphere. To this was added 18.6 ml of tri-n-butyl tin hydride and 0.43 g of AIBN. The resultant mixture was heated to reflux temperature for 30 minutes. At that time an additional 0.43 g of AIBN was added. The resultant mixture was heated at reflux temperature for an additional 30 minutes, cooled and transferred to a separatory funnel. To this was added 100 ml of 1N hydrochloric acid and 100 ml of ethyl acetate. The resultant mixture was shaken and separated. The organic layer was washed with brine, dried over sodium sulfate, filtered, evaporated and subsequently chased with chloroform to give an orange/red oil which was taken up in 50 ml of chloroform and filtered. The filtrate was chromatographed on a silica gel column using an 8000 ml gradient of 10-40% ethyl acetate in hexane. Those fractions identified as containing product were evaporated and chased with chloroform. To these fractions were added 15 ml of hexane and the resultant solution was heated slightly. A precipitate formed which was diluted to about 25 ml with additional hexane. The resultant mixture was triturated for about 2 hours, filtered and then washed with hexane to yield 1.94 g of the desired product, m.p. 133.5°-135° C.

Provenance & Evidence