Réaction #76474

Équation de réaction

2,3,5-Trimethyl-4-hydroxyphenylthiocyanate

LiAlH4

→

2,3,5-trimethyl-4-hydroxybenzenethiol

Rendement 103.4%

Solvants

ether

tetrahydrofuran

ether

Conditions de réaction

Traitement

1. 1
   workup.WAITAfter a further hour at 20° C.
2. 2
   Autrethe unreacted LiAlH4 was destroyed
3. 3
   workup.ADDITIONadding moist ether (50 mL), H2O (50 mL), and 1 N HCl (50 mL)
4. 4
   workup.ADDITIONA further 50 mL of water was added
5. 5
   Autrethe organic phase was separated
6. 6
   Lavagewashed with water (2×50 mL), NaHCO3 solution (2×50 mL), water (2×50 mL), and saturated NaCl (50 mL)
7. 7
   SéchageThe organic phase was dried over anhydrous MgSO4
8. 8
   Filtrationfiltered
9. 9
   Autrethe solvent removed under reduced pressure

Mode opératoire

2,3,5-Trimethyl-4-hydroxyphenylthiocyanate (2 g, 10.35 mmol) was dissolved in 100 mL of anhydrous ether containing 25 mL of anhydrous tetrahydrofuran. This solution was added dropwise over 1 h to 100 mL of anhydrous ether containing LiAlH4 (0.9 g, 24 mmol) at room temperature. After a further hour at 20° C., the unreacted LiAlH4 was destroyed by cooling the heterogeneous mixture to 0° C. and adding moist ether (50 mL), H2O (50 mL), and 1 N HCl (50 mL). A further 50 mL of water was added and the organic phase was separated and washed with water (2×50 mL), NaHCO3 solution (2×50 mL), water (2×50 mL), and saturated NaCl (50 mL). The organic phase was dried over anhydrous MgSO4 and filtered and the solvent removed under reduced pressure. Silica gel column chromatography with 5% ethyl acetate in hexane gave 1.8 g (90%) of 2,3,5-trimethyl-4-hydroxybenzenethiol as a white powder, mp 86° C. [Lit. 1 mp 86° C.].

Source