Reaction #1726678

Reaction equation

hydrochloric acid

1-tert-butoxycarbonyl-4-[2-(4-methylphenylsulfanyl)phenyl]piperidin-4-ol

NaOH

→

4-[2-(4-Methylphenylsulfanyl)phenyl]-3,6-dihydro-2H-pyridine

Solvents

acetic acid

Conditions

Workup

1. 1
   Temperatureunder reflux overnight
2. 2
   Extractionthe unclear solution was extracted with ethyl acetate (2×40 ml)
3. 3
   DryingThe combined organic phases were dried (MgSO4)
4. 4
   Otherthe solvents evaporated in vacuo
5. 5
   workup.DISSOLUTIONThe crude material (0.48 g) was dissolved in ethyl acetate (3.2 mL) at 50° C.
6. 6
   workup.ADDITIONa solution of oxalic acid (0.11 g) in EtOH (3.2 mL) was slowly added
7. 7
   OtherThe target compound was collected as a white oxalic salt
8. 8
   OtherRT=2.24

Procedure

Concentrated aq hydrochloric acid (10 ml) was added to a stirred solution of 1-tert-butoxycarbonyl-4-[2-(4-methylphenylsulfanyl)phenyl]piperidin-4-ol (0.84 g, 2.1 mmol) in acetic acid (30 mL). The solution was boiled under reflux overnight, cooled to room temperature and then stirred in an ice bath. An aqueous solution of NaOH (9.1 M, 40 mL) was slowly added and the unclear solution was extracted with ethyl acetate (2×40 ml). The combined organic phases were dried (MgSO4) and the solvents evaporated in vacuo. The crude material (0.48 g) was dissolved in ethyl acetate (3.2 mL) at 50° C. and a solution of oxalic acid (0.11 g) in EtOH (3.2 mL) was slowly added. The target compound was collected as a white oxalic salt. 1H (DMSO-d6) δ 7.3-7.2 (m, 7H); 7.15 (m, 1H); 7.00 (m, 1H); 5.6 (d, 1H); 3.7 (d, 2H); 3.25 (t, 2H); 2.6 (m, 2H); 2.3 (s, 3H). LC/MS (m/z) 282.2 (MH+); RT=2.24; purity (UV, ELSD): 99%, 100%; yield: 0.31 g (40%).

Source