Ethanol → N-Methyl-3-pyrrolidinyl Cyclopentylmandelate

HRID 656164Notes

Reaction equation

HRID 656164 reaction equation
[CH:1]1([C:6]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)([OH:11])[C:7]([O:9][CH3:10])=[O:8])[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:18][N:19]1[CH2:23]C[CH:21](O)[CH2:20]1.CCOC(C)=O.CCO>CCCCCCC>[CH:1]1([C:6]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)([OH:11])[C:7]([O:9][CH:10]2[CH2:21][CH2:20][N:19]([CH3:23])[CH2:18]2)=[O:8])[CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 702EthanolHCID 8857Ethyl AcetateHCID 89233Methyl cyclopentylmandelateHCID 930741-Methyl-3-pyrrolidinol

Product 1

HCID 25727N-Methyl-3-pyrrolidinyl CyclopentylmandelateYield 72%

Reagents, catalysts & solvents 1

HCID 8900HeptaneSolvent2×

Procedure

A solution of 2 (2.20 g, 9.4 mmol) and N-methyl-3-pyrrolidinol (3, 1.30 g, 13 mmol) in 40 ml of n-heptane was heated until 20 ml of heptane had been distilled. About 0.003 g of sodium was added, and the solution was stirred and heated for 2 h as the distillation was continued. More heptane was added at such a rate as to keep the reaction volume constant. Additional sodium was added at the end of an hour. The solution was then cooled and extracted with 3N HCl. The acid extract was made alkaline with concentrated NaOH and extracted three times with ether. Removal of the dried ether solution gave a crude oil. Flash chromatography of the crude product on silica gel with 8:1 EtOAc:EtOH gave pure product 4 (2.053 g, 72%). Analysis for C18H25NO3. Calcd: C, 71.26; H, 8.31; N, 4.62. Found: C, 71.55; H, 8.44; N, 4.68. 1H NMR (CDCl3, 500 MHz): 1.27-1.35, 1.40-1.47, 1.54-1.60, 1.75-1.90 [8H, m, (CH2)4], 2.12-2.30, 2.52-2.57, 2.64-2.81 (6H, m CH2NCH2CH2), 2.33, 2.36 (3H, 2s, NCH3), 2.93 [(1H, p, CHC(OH)], 3.83 (1H, bs, OH), 5.23 (1H, m, CO2CH), 7.23-7.36, 7.64-7.67 (5H, m, Ph) ppm.

Workup

  1. distillationhad been distilled
  2. additionAbout 0.003 g of sodium was added
  3. temperatureheated for 2 h as the distillation
  4. additionMore heptane was added at such a rate as
  5. additionAdditional sodium was added at the end of an hour
  6. temperatureThe solution was then cooled
  7. extractionextracted with 3N HCl
  8. extractionThe acid extract
  9. extractionextracted three times with ether
  10. customRemoval of the dried ether solution
  11. customgave a crude oil

Sources & evidence

ORD record
ord-13d9a70bb3a1458f92d034e30ce0729a
Source dataset
uspto-grants-2011_12
Patent number
US08071639B2

Reaction notes

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