Hydrochloric Acid → Tiagabine

HRID 619242Notes

Reaction equation

HRID 619242 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

Reactant 2

HCID 313Hydrochloric AcidHCID 11555813PIP017

Product 1

HCID 60648TiagabineYield 90.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
88 °C

Procedure

To a 1 L flask, 50 g of tiagabine ethyl ester, 575 ml of water and 25 g of conc. hydrochloric acid were charged. The mixture was heated to reflux for 1 hour and then ethanol/water, a total of 200 ml, was distilled off over a period of 4 hours. The reaction solution was cooled to 88° C. and then an additional 23.5 g of conc. hydrochloric acid was added. The solution was gradually cooled to room temperature (22° C.) while the reaction was stirred 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 42.0 g of Tiagabine, hydrochloride.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 1 hour
  3. distillationethanol/water, a total of 200 ml, was distilled off over a period of 4 hours
  4. additionan additional 23.5 g of conc. hydrochloric acid was added
  5. temperatureThe solution was gradually cooled to room temperature (22° C.) while the reaction
  6. filtrationThe resulting precipitate was collected by filtration
  7. washwas washed with 20 ml of water
  8. customThe product was dried under vacuum at room temperature

Sources & evidence

ORD record
ord-ac47111540ec4257b45a58f85740db35
Source dataset
uspto-grants-1999_09
Patent number
US05958951

Reaction notes

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