Reaction #3039

Reaction equation

5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-[2-(acetyloxy) ethyl]-2-thioxo-4-thiazolidinone

Tri-n-butyl tin hydride

AIBN

→

desired titled compound

Yield 59.7%

5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-[2-(acetyloxy)ethyl]-4-thiazolidinone

Yield 59.7%

Solvents

toluene

Conditions

Workup

1. 1
   Temperaturethe solution heated
2. 2
   Temperatureat reflux temperature for an additional 10 minutes
3. 3
   TemperatureAfter cooling
4. 4
   Washthe mixture was washed with 1.25l of 1N hydrochloric acid
5. 5
   Othera precipitate separated
6. 6
   OtherThe liquid portion was decanted off
7. 7
   Otherthe resulting residue was purified by chromatography over silica gel
8. 8
   Washeluting with a gradient of 25-50% of ethyl acetate in hexane
9. 9
   Concentrationconcentrated in vacuo

Procedure

Under a nitrogen atmosphere, 82.2 g of 5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-[2-(acetyloxy) ethyl]-2-thioxo-4-thiazolidinone in 950 ml of toluene was heated to 65° C. Tri-n-butyl tin hydride (219.7 g) and AIBN (4.65 g) were added and the solution heated at reflux temperature for an additional 10 minutes. After cooling, the mixture was washed with 1.25l of 1N hydrochloric acid followed by 500 ml of a saturated sodium chloride solution. The organic layer was stripped and allowed to stand overnight, during which time a precipitate separated. The liquid portion was decanted off, and the resulting residue was purified by chromatography over silica gel, eluting with a gradient of 25-50% of ethyl acetate in hexane. The appropriate fractions were combined and concentrated in vacuo to provide 45.7 g of the desired titled compound, m.p.=152°-155° C.

Source