3-Mercaptopropionic Acid → 3-(4-METHYL-BENZYLSULFANYL)-PROPIONIC ACID

A solution of betamercaptopropionic acid (5.3 g, 50 mMol) in water (95 ml) was diluted with absolute ethanol (80 ml) and triethylamine (15 ml). While this solution was mechanically stirred and cooled with an ice bath, a solution of 4-methylbenzyl bromide (9.4 g) in ethanol (80 ml) was added over a period of 15 minutes. The ice bath was removed and the reaction mixture was stirred at room temperature for 2.5 hours. The mixture was then concentrated in vacuo and the residue was suspended in water (100 ml). As the pH of the suspension was adjusted to 10, the residue dissolved. The resulting solution was extracted three times with di-ethyl ether and the aqueous phase was acidified to pH 1 with concentrated HCl. An oily residue separated. The mixture was then exhaustively extracted with di-ethyl ether, the ether extracted was dried over MgSO4 and concentrated to an oil. The latter solidified on standing and the solid residue was recrystallized from ethyl acetate-liquid petroleum. The yield was 7.9 g (75%), m.p. 75.8° C., NMR (CDCl3) 11.5 (s, 1H), 7.09 (q, 4H), 3.67 (s, 2H), 2.60 (m, 4H), 2.30 (s, 3H).

1. temperaturecooled with an ice bath
2. customThe ice bath was removed
3. stirringthe reaction mixture was stirred at room temperature for 2.5 hours
4. concentrationThe mixture was then concentrated in vacuo
5. dissolutionthe residue dissolved
6. extractionThe resulting solution was extracted three times with di-ethyl ether
7. customAn oily residue separated
8. extractionThe mixture was then exhaustively extracted with di-ethyl ether
9. extractionthe ether extracted
10. dry with materialwas dried over MgSO4
11. concentrationconcentrated to an oil
12. customthe solid residue was recrystallized from ethyl acetate-liquid petroleum

ORD record

ord-b4a95ca600f9410c94f6c8188a1f87c4

Source dataset

uspto-grants-1981_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04285858