Water → HCID 14796234, compound

To a solution of 2,6-di-tert-butyl-4-mercaptophenol (II) (590 mg; 2.48 mmol) in dry ether (10 ml), triethylamine (303 mg; 3 mmol) was added, and a solution of ethyl 4-bromocrotonate (580 mg; 3 mmol) in dry ether (5 ml) was added while cooling with ice, followed by stirring at room temperature for 2 hours. The reaction mixture was combined with water (50 ml) and extracted with ether (50 ml). The extract was washed with water (50 ml) two times and concentrated under reduced pressure. The crude intermediate product as pale yellow oil was dissolved in ethanol (30 ml), 10 % sodium hydroxide solution (3 ml) was added thereto, and the resultant mixture was stirred at room temperature for 2 hours. To the reaction mixture, acetic acid (2 ml) was added, and the resulting mixture was concentrated under reduced pressure to make a volume of about 10 ml, which was extracted with ethyl acetate (50 ml). The extract was washed with water (50 ml) two times, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residual oil was chromatographed on silica gel and eluted with ethyl acetate. The collected fractions were concentrated under reduced pressure, and the crystalline residue was recrystallized from n-pentane to give the objective compound (Ih) (270 mg). m.p., 104°-106° C. Yield, 34 %.

1. temperaturewhile cooling with ice
2. extractionextracted with ether (50 ml)
3. washThe extract was washed with water (50 ml) two times
4. concentrationconcentrated under reduced pressure
5. dissolutionThe crude intermediate product as pale yellow oil was dissolved in ethanol (30 ml)
6. addition10 % sodium hydroxide solution (3 ml) was added
7. stirringthe resultant mixture was stirred at room temperature for 2 hours
8. additionTo the reaction mixture, acetic acid (2 ml) was added
9. concentrationthe resulting mixture was concentrated under reduced pressure
10. extractionwas extracted with ethyl acetate (50 ml)
11. washThe extract was washed with water (50 ml) two times
12. dry with materialdried over anhydrous sodium sulfate
13. concentrationconcentrated under reduced pressure
14. customThe residual oil was chromatographed on silica gel
15. washeluted with ethyl acetate
16. concentrationThe collected fractions were concentrated under reduced pressure
17. customthe crystalline residue was recrystallized from n-pentane
18. customto give the objective compound (Ih) (270 mg)
19. customm.p., 104°-106° C
20. customYield

ORD record

ord-c4a8ce27bf82490992c42e161e9a9be5

Source dataset

uspto-grants-1992_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05084214