Reaction #2507836

Reaction equation

pentane

3-methyl-2-butenoic acid

4-methoxythiophenol

piperidine

→

3-(4-methoxyphenylthio)-3-methyl-butyric acid

Solvents

ethyl acetate

Conditions

Workup

1. 1
   Temperaturecooled to room temperature
2. 2
   Washthe resulting solution was washed with 1M aqueous HCl (50 ml×2), water (50 ml), and saturated aqueous NaCl (50 ml)
3. 3
   DryingThe organic solution was thereafter dried over NaSO4
4. 4
   OtherConcentration of this organic solution under reduced pressure afforded an oil and 2 days incubation at −20° C.
5. 5
   Otheryielded a crystalline solid
6. 6
   Otherwas then crushed
7. 7
   Filtrationfiltered
8. 8
   WashThe solid was washed
9. 9
   Filtrationon filter paper with pentane (20 ml, 2 times)

Procedure

A heavy-walled screw-cap tube was charged with 3-methyl-2-butenoic acid (13.86 gm) 3,3-dimethylacrylic acid, (138.4 mmol), 4-methoxythiophenol (143.2 mmol), and piperidine (41.6 mmol) [Aldrich]. The mixture was heated to 105-110° C. for 32 hours, then cooled to room temperature. The reaction mixture was dissolved in ethyl acetate (EtOAc) (700 ml) with stirring, and the resulting solution was washed with 1M aqueous HCl (50 ml×2), water (50 ml), and saturated aqueous NaCl (50 ml). The organic solution was thereafter dried over NaSO4. Concentration of this organic solution under reduced pressure afforded an oil and 2 days incubation at −20° C. yielded a crystalline solid. Forty ml of pentane were added to the solid, which was then crushed and filtered. The solid was washed on filter paper with pentane (20 ml, 2 times) to yield the product 3-(4-methoxyphenylthio)-3-methyl-butyric acid, as pale yellow crystals (31.4 grams, 94.4% yield, m.p. 62-64° C.), [1H-NMR(CDCl3): d7.5 (t, 2H, J=8 Hz), d6.9 (t, 2H, J=6.7 Hz), d3.9 (s, 3H, J=16.1 Hz), d2.6 (s, 2H), d1.3 (s, 6H)].

Source