Hydrochloric Acid → 4-(3,4-dihydro-6,7-dimethoxy-1-methyl-1H-2-benzopyran-1-yl)piperidine

HRID 2255144

Reaction equation

HRID 2255144 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH2:11][CH2:12][OH:13])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[NH:14]1[CH2:19][CH2:18][CH:17]([C:20](=O)[CH3:21])[CH2:16][CH2:15]1.Cl>C(O)C>[CH3:1][O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][C:6]2[C:20]([CH:17]3[CH2:18][CH2:19][NH:14][CH2:15][CH2:16]3)([CH3:21])[O:13][CH2:12][CH2:11][C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 819113,4-Dimethoxyphenethyl alcoholHCID 27237641-(Piperidin-4-yl)ethan-1-one

Product 1

HCID 200879464-(3,4-dihydro-6,7-dimethoxy-1-methyl-1H-2-benzopyran-1-yl)piperidineYield 86%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 200 g of 3,4-dimethoxybenzeneethanol and 163,7 g of 1-(4-piperidinyl)ethanone in 800 ml of ethanol saturated with anhydrous hydrochloric acid was stirred for 15 h at ambient temperature. The mixture was concentrated under vacuum, and the concentrate was diluted with 500 ml of ethanol after which the hydrochloride precipitated. After filtration the hydrochloride was dissolved in water and sodium hydroxide until the pH was 12. The base was extracted with dichloromethane, and the organic phase was washed with water, dried and evaporated to yield 251 g (86,5%) of crude 4-(3,4-dihydro-6,7-dimethoxy-1-methyl-1H-2-benzopyran-1-yl)piperidine.

Workup

  1. concentrationThe mixture was concentrated under vacuum
  2. additionthe concentrate was diluted with 500 ml of ethanol after which the hydrochloride
  3. customprecipitated
  4. filtrationAfter filtration the hydrochloride
  5. dissolutionwas dissolved in water
  6. extractionThe base was extracted with dichloromethane
  7. washthe organic phase was washed with water
  8. customdried
  9. customevaporated

Sources & evidence

ORD record
ord-9f3cbcac96d64b3f8afea45a665b299c
Source dataset
uspto-grants-1993_08
Patent number
US05238939

Linked notes

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