Potassium Hydroxide → 4-(5-Fluoro-2-benzofuranyl)piperidine

HRID 2057429Notes

Reaction equation

HRID 2057429 reaction equation
C(OC([N:6]1[CH2:11][CH2:10][CH:9]([C:12]2[O:13][C:14]3[CH:20]=[CH:19][C:18]([F:21])=[CH:17][C:15]=3[CH:16]=2)[CH2:8][CH2:7]1)=O)C.[OH-].[K+]>C(O)CO.C1(C)C=CC=CC=1>[F:21][C:18]1[CH:19]=[CH:20][C:14]2[O:13][C:12]([CH:9]3[CH2:8][CH2:7][NH:6][CH2:11][CH2:10]3)=[CH:16][C:15]=2[CH:17]=1

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 53928071HCID 53928071, compound

Product 1

HCID 233123124-(5-Fluoro-2-benzofuranyl)piperidine

Reagents, catalysts & solvents 2

HCID 174Ethylene GlycolSolventHCID 1140TolueneSolvent

Procedure

5.9 g (about 0.02 mole) of 4-(5-fluoro-2-benzofuranyl)-1-piperidinecarboxylic acid ethyl ester is dissolved in 65 ml of ethylene glycol. After the addition of 19.4 g of 86% potassium hydroxide, the cloudy solution formed is heated, with vigorous stirring, for 18 hours at 160°. The reaction solution is thereupon cooled to 100°, diluted with 65 ml of toluene and then cooled to 20°. The organic phases are firstly extracted twice with one liter of water each time, then four times with 200 ml of a 10% solution of methane sulphonic acid in water. The methanesulphonic acid solution is thereupon brought to the pH-value of 12 by the addition of 30% sodium hydroxide solution, and is subsequently extracted with one liter of chloroform. The chloroform solution is dried with sodium sulphate, filtered and concentrated by evaporation to thus obtain crude 4-(5-fluoro-2-benzofuranyl)-piperidine. The base is distilled by molecular distillation in high vacuum. The fraction distilling at 190°-200° and 0.05 Torr is 4-(5-fluoro-2-benzofuranyl)-piperidine. The hydrochloride is prepared with hydrogen chloride in ethyl acetate and recrystallised from ethyl acetate, whereupon it melts at 235°-237°.

Workup

  1. customthe cloudy solution formed
  2. temperatureis heated, with vigorous stirring, for 18 hours at 160°
  3. temperatureThe reaction solution is thereupon cooled to 100°
  4. temperaturecooled to 20°
  5. extractionThe organic phases are firstly extracted twice with one liter of water each time
  6. additionThe methanesulphonic acid solution is thereupon brought to the pH-value of 12 by the addition of 30% sodium hydroxide solution
  7. extractionis subsequently extracted with one liter of chloroform
  8. dry with materialThe chloroform solution is dried with sodium sulphate
  9. filtrationfiltered
  10. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-a0c0e4efc8f040689ca38c809cfb7c3f
Source dataset
uspto-grants-1980_07
Patent number
US04210655

Reaction notes

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