Boron tribromide → 4-Hydroxybenzothiazole
Reaktionsgleichung
B(Br)(Br)Br.C[O:6][C:7]1[C:12]2[N:13]=[CH:14][S:15][C:11]=2[CH:10]=[CH:9][CH:8]=1>C(Cl)Cl>[OH:6][C:7]1[C:12]2[N:13]=[CH:14][S:15][C:11]=2[CH:10]=[CH:9][CH:8]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Reaktionsbedingungen
- Temperatur
- 40 °C
Versuchsvorschrift
Boron tribromide (3.09 ml, 1M solution in DCM, 3.09 mmol) was added dropwise at 0° C. to a stirred solution of 4-methoxy-benzothiazole (510 mg, 3.09 mmol) in dry DCM (30ml). The resulting solution was warmed to 40° C. and allowed to stir overnight. The resulting solution was concentrated in vacuo and diluted with water and HCl (2N). The aqueous phase was neutralised to pH˜7 with NaHCO3 and the solution extracted with EtOAc (3×100 ml) and the combined organic extracts dried (MgSO4) and the solvent removed in vacuo. The resulting oil was purified by flash chromatography eluting silica gel with hexane:EtOAc [4:1] to hexane:EtOAc [7:3] to give the title compound as a tan solid (730 mg, 80%); δH (300 MHz, CDCl3) 7.59 (1H, s, CH), 7.46 (1H, dd, Ar), 7.36 (1H, t, Ar), 7.02 (1H, dd, Ar).