Potassium Hydroxide → HCID 21519695, compound

HRID 1283302Notes

Reaction equation

HRID 1283302 reaction equation
C(OC([N:6]1[CH2:11][CH2:10][CH:9]([C:12]2[S:16][C:15]3[CH:17]=[CH:18][CH:19]=[CH:20][C:14]=3[CH:13]=2)[CH:8]([CH3:21])[CH2:7]1)=O)C.[OH-].[K+]>C(O)CO>[CH3:21][CH:8]1[CH:9]([C:12]2[S:16][C:15]3[CH:17]=[CH:18][CH:19]=[CH:20][C:14]=3[CH:13]=2)[CH2:10][CH2:11][NH:6][CH2:7]1

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 54006113HCID 54006113, compound

Product 1

HCID 21519695HCID 21519695, compound

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent

Procedure

The whole amount of the 3-methyl-4(benzo[b]thien-2-yl)-1-piperidinecarboxylic acid ethyl ester obtained as crude product according to the following section (a) is dissolved in 100 ml of ethylene glycol. There is then added 30 g of solid potassium hydroxide, and the resulting cloudy solution is heated, with vigorous stirring, for 15 hours at 160°. The reaction solution is subsequently cooled to 20°, and extracted 3 times with 150 ml of toluene each time. The combined toluene solutions are washed 5 times with 250 ml of water each time, and subsequently extracted twice with 200 ml of 2N hydrochloric acid each time. The acid solutions are combined; the pH-value is adjusted to 12 by the addition of 10% sodium hydroxide solution, and extraction is performed with 500 ml of chloroform. The chloroform solution is dried with sodium sulphate, filtered, and concentrated by evaporation to obtain crude 3-methyl-4-(benzo[b]thien-2-yl)-piperidine. The crude base is distilled in a bulb tube (molecular distillation) under high vacuum (0.20 Torr at a bath temperature of 170°-190°). From the distillate there is prepared the hydrochloride with hydrogen chloride in ethyl acetate; the hydrochloride is recrystallised from acetone and then melts at 253°-255°.

Workup

  1. temperaturethe resulting cloudy solution is heated, with vigorous stirring, for 15 hours at 160°
  2. temperatureThe reaction solution is subsequently cooled to 20°
  3. extractionextracted 3 times with 150 ml of toluene each time
  4. washThe combined toluene solutions are washed 5 times with 250 ml of water each time
  5. extractionsubsequently extracted twice with 200 ml of 2N hydrochloric acid each time
  6. additionthe pH-value is adjusted to 12 by the addition of 10% sodium hydroxide solution, and extraction
  7. dry with materialThe chloroform solution is dried with sodium sulphate
  8. filtrationfiltered
  9. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-727f3723db7f46a7a47b9a9ec438cfbb
Source dataset
uspto-grants-1976_08
Patent number
US03974280

Reaction notes

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