Potassium Hydroxide → HCID 23312203, compound

HRID 2057420Notes

Reaction equation

HRID 2057420 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]([Cl:21])=[CH:17][C:15]=3[CH:16]=2)[CH2:8][CH2:7]1)=O)C.[OH-].[K+]>C(O)CO>[Cl: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

4

Reactant 2

HCID 14797Potassium HydroxideHCID 54111820HCID 54111820, compound

Product 1

HCID 23312203HCID 23312203, compound

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

11.5 g of 4-(5-chloro-2-benzofuranyl)-1-piperidinecarboxylic acid ethyl ester is dissolved in 75 ml of ethylene glycol. After the addition of 50 ml of a 50% aqueous potassium hydroxide solution, the formed cloudy solution is heated, with vigorous stirring, for 15 hours at 160°; the reaction solution is thereupon cooled to 20°, and extracted twice with 500 ml of ethyl acetate each time. The organic phases are washed five times with 1 liter of water each time, dried over sodium sulphate, filtered, and concentrated by evaporation. The residue is dissolved in 300 ml of a 10% solution of methanesulphonic acid in water, and the acid solution extracted with ether. The aqueous solution is then adjusted by addition of 10% sodium hydroxide solution to have a pH value of 12, and extracted with 1 liter of chloroform. The chloroform solution is dried with sodium sulphate, filtered, and concentrated by evaporation to obtain crude 4-(5-chloro-2-benzofuranyl)-piperidine. The free base melts at 77°-78° after recrystallisation from hexane. The hydrochloride is prepared with hydrogen chloride in ethyl acetate, and recrystallised from ethyl acetate, whereupon its melts at 252°-254°.

Workup

  1. temperaturethe formed cloudy solution is heated, with vigorous stirring, for 15 hours at 160°
  2. temperaturethe reaction solution is thereupon cooled to 20°
  3. extractionextracted twice with 500 ml of ethyl acetate each time
  4. washThe organic phases are washed five times with 1 liter of water each time
  5. dry with materialdried over sodium sulphate
  6. filtrationfiltered
  7. concentrationconcentrated by evaporation
  8. dissolutionThe residue is dissolved in 300 ml of a 10% solution of methanesulphonic acid in water
  9. extractionthe acid solution extracted with ether
  10. additionThe aqueous solution is then adjusted by addition of 10% sodium hydroxide solution
  11. extractionextracted with 1 liter of chloroform
  12. dry with materialThe chloroform solution is dried with sodium sulphate
  13. filtrationfiltered
  14. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-6606e34b11974342894b266fc94610d9
Source dataset
uspto-grants-1980_07
Patent number
US04210655

Reaction notes

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