Réaction #6630

Équation de réaction

4,4-dimethylthiochroman

Compound 61

4,4-dimethylthiochroman

acetyl chloride

water

hydrogen chloride

→

title compound

4,4-Dimethyl-6-acetylthiochroman

Solvants

benzene

Conditions de réaction

Traitement

1. 1
   Températureheated
2. 2
   Températureat reflux for 0.5 hours
3. 3
   TempératureAfter being cooled to room temperature
4. 4
   Autrethe organic layer was separated
5. 5
   Extractionthe aqueous layer extracted with 5×50 ml benzene
6. 6
   Lavagewashed with 5% sodium carbonate, water, saturated NaCl
7. 7
   Séchagedried (MgSO4)
8. 8
   AutreThe solvent was removed in vacuo
9. 9
   Autrethe residue purified by flash chromatography (silica; 5% ethyl acetate in hexanes)
10. 10
    workup.DISTILLATIONfollowed by kugelrohr distillation (150 degrees C., 0.7 mm)

Mode opératoire

A solution of 14.3g (80.21 mmol) of 4,4-dimethylthiochroman (Compound 61) and 6.76g (86.12 mmol) of acetyl chloride in 65 ml benzene was cooled in an ice bath and treated dropwise with 26.712g (102.54 mmol) of stannic chloride. The mixture was stirred at room temperature for 12 hours, then treated with 65 ml water and 33 ml conc. hydrogen chloride and heated at reflux for 0.5 hours. After being cooled to room temperature, the organic layer was separated and the aqueous layer extracted with 5×50 ml benzene. The recovered organic fractions were combined and washed with 5% sodium carbonate, water, saturated NaCl and then dried (MgSO4). The solvent was removed in vacuo and the residue purified by flash chromatography (silica; 5% ethyl acetate in hexanes) followed by kugelrohr distillation (150 degrees C., 0.7 mm) to give the title compound as a pale yellow oil. PMR (CDCl3) & 1.35 (6H, s), 1.92-1.98 (2H, m) 2.54 (3H, s), 3.02-3.08 (2H, m), 7.13 (1H, d, J~8.6 Hz), 7.58 (1H, dd, J~8.6 Hz, Hz), 7.99 (1H, d, J~2Hz).

Source