Réaction #50550

Équation de réaction

3-bromobenzyl bromide

thioglycolic acid

potassium hydroxide

→

3-bromophenylmethylthioacetic acid

Rendement 92.0%

Solvants

ethanol

water

Conditions de réaction

Traitement

1. 1
   TempératureThe reaction was heated
2. 2
   Températureat reflux for 3.5 h
3. 3
   Températurecooled
4. 4
   Autrethe ethanol was evaporated
5. 5
   AutreThe residue was quenched with water (100 mL)
6. 6
   Extractionthe mixture was extracted with ether (50 mL)
7. 7
   Extractionextracted with ethyl acetate (2×100 mL)
8. 8
   Autrethe organic phase was dried
9. 9
   AutreEvaporation of the solvent
10. 10
    Lavageby washing of the residue with hexane

Mode opératoire

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.

Source