Reaktion #3042

Reaktionsgleichung

tri-n-butyl tin hydride

AIBN

AIBN

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

hydrochloric acid

→

desired product

Ausbeute 29.8%

5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-3-(ethylmethylamino)-4-thiazolidinone

Ausbeute 29.8%

Lösungsmittel

hexane

chloroform

toluene

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto reflux temperature for 30 minutes
2. 2
   Temperaturat reflux temperature for an additional 30 minutes
3. 3
   Temperaturcooled
4. 4
   Sonstigetransferred to a separatory funnel
5. 5
   Sonstigeseparated
6. 6
   WaschenThe organic layer was washed with brine
7. 7
   Trocknendried over sodium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigeevaporated
10. 10
    Sonstigeto give an orange/red oil which
11. 11
    Filtrationfiltered
12. 12
    SonstigeThe filtrate was chromatographed on a silica gel column
13. 13
    workup.ADDITIONas containing product
14. 14
    Sonstigewere evaporated
15. 15
    workup.ADDITIONTo these fractions were added 15 ml of hexane
16. 16
    Temperaturthe resultant solution was heated slightly
17. 17
    SonstigeA precipitate formed which
18. 18
    SonstigeThe resultant mixture was triturated for about 2 hours
19. 19
    Filtrationfiltered
20. 20
    Waschenwashed with hexane

Vorschrift

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.

Quelle