Hydrochloric Acid → Tiagabine

HRID 619241Notes

Reaction equation

HRID 619241 reaction equation
CC[O:3][C:4]([C@H:6]1[CH2:11][N:10]([CH2:12][CH2:13][CH:14]=[C:15]([C:22]2[S:26][CH:25]=[CH:24][C:23]=2[CH3:27])[C:16]2[S:20][CH:19]=[CH:18][C:17]=2[CH3:21])[CH2:9][CH2:8][CH2:7]1)=[O:5].Cl>O>[CH3:27][C:23]1[CH:24]=[CH:25][S:26][C:22]=1[C:15]([C:16]1[S:20][CH:19]=[CH:18][C:17]=1[CH3:21])=[CH:14][CH2:13][CH2:12][N:10]1[CH2:11][C@H:6]([C:4]([OH:5])=[O:3])[CH2:7][CH2:8][CH2:9]1

Participants

4

Conditions

Temperature
57.5 °C

Procedure

To a 1 L flask, 50 g of tiagabine ethyl ester, 750 ml of water and 11 g of conc. hydrochloric acid were charged. The mixture was heated to reflux for 2 hours and then ethanol/water, a total of 400 ml, was distilled off over a period of 4 hours. The remaining solution was stirred under reflux overnight. It was cooled to 55-60° C. and then an additional 37.5 g of conc. hydrochloric acid was added over a period of 5 min. The solution was cooled to 50-52° C. and was stirred at this temperature for 18 hours. The resulting precipitate was collected by filtration and was washed with 20 ml of water. The product was dried under vacuum at room temperature to give 40.5 g of Tiagabine, hydrochloride.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2 hours
  3. distillationethanol/water, a total of 400 ml, was distilled off over a period of 4 hours
  4. temperatureunder reflux overnight
  5. additionan additional 37.5 g of conc. hydrochloric acid was added over a period of 5 min
  6. temperatureThe solution was cooled to 50-52° C.
  7. stirringwas stirred at this temperature for 18 hours
  8. filtrationThe resulting precipitate was collected by filtration
  9. washwas washed with 20 ml of water
  10. customThe product was dried under vacuum at room temperature

Sources & evidence

ORD record
ord-9ab4f5ca5ae6452fb3d6404f2a9ea59e
Source dataset
uspto-grants-1999_09
Patent number
US05958951

Reaction notes

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