Reaktion #50550

Reaktionsgleichung

3-bromobenzyl bromide

thioglycolic acid

potassium hydroxide

→

3-bromophenylmethylthioacetic acid

Ausbeute 92.0%

Lösungsmittel

ethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was heated
2. 2
   Temperaturat reflux for 3.5 h
3. 3
   Temperaturcooled
4. 4
   Sonstigethe ethanol was evaporated
5. 5
   SonstigeThe residue was quenched with water (100 mL)
6. 6
   Extraktionthe mixture was extracted with ether (50 mL)
7. 7
   Extraktionextracted with ethyl acetate (2×100 mL)
8. 8
   Sonstigethe organic phase was dried
9. 9
   SonstigeEvaporation of the solvent
10. 10
    Waschenby washing of the residue with hexane

Vorschrift

To a solution of 3-bromobenzyl bromide (23.75 g, 90 mmol) and thioglycolic acid (11.42 g, 120 mmol) in ethanol (150 mL) was added potassium hydroxide (14.24 g, 250 mmol) in water (50 mL). The reaction was heated at reflux for 3.5 h, cooled and the ethanol was evaporated. The residue was quenched with water (100 mL) and the mixture was extracted with ether (50 mL). The aqueous layer was acidified to pH 1 with concentrated hydrochloric acid, extracted with ethyl acetate (2×100 mL) and the organic phase was dried. Evaporation of the solvent followed by washing of the residue with hexane afforded 3-bromophenylmethylthioacetic acid as a white solid (92%), mp 90°-91° C.: 1H NMR (CDCl3) δ3.10 (s, 2H), 3.82 (s, 2H), 7.20-7.29 (m, 2H), 7.39-7.42 (dd, 1H), 7.52 (d, 1H); IR (KBr) 1706 cm-1 ; Mass spectrum m/z 280 (M+NH4); Anal. calcd. for C9H9O2SBr: C 41.39, H 3.47, S 12.28; Found C 41.43, H 3.49, S 12.10.

Quelle