Acetic Acid → Ethyl 4-(dibenzylamino)-2-ethylcyclopentanecarboxylate

HRID 1969615Notes

Reaction equation

HRID 1969615 reaction equation
[CH2:1]([CH:3]1[CH2:7][C:6](=O)[CH2:5][CH:4]1[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH3:2].CC(O)=O.[CH2:18]([NH:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+].C([O-])(O)=O.[Na+]>ClCCCl>[CH2:26]([N:25]([CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[CH:6]1[CH2:5][CH:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:3]([CH2:1][CH3:2])[CH2:7]1)[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 7656DibenzylamineHCID 516892Sodium Bicarbonate2×HCID 5049666Sodium triacetoxyborohydrideHCID 58010012Cyclopentanecarboxylic acid, 2-ethyl-4-oxo-, ethyl ester

Product 1

HCID 58009964Ethyl 4-(dibenzylamino)-2-ethylcyclopentanecarboxylateYield 72%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

A round bottom flask was charged with ethyl 2-ethyl-4-oxocyclopentanecarboxylate (95.9 g, 521 mmol, Preparation #W.1) and DCE (1.8 L). The solution was cooled to about 0° C. and AcOH (45 mL, 780 mmol) and dibenzylamine (120 mL, 625 mmol) were added dropwise, resulting in formation of a thick suspension. The reaction mixture was warmed to about 10° C. and additional DCE (500 mL) was added. NaBH(OAc)3 (166 g, 781 mmol) was added portionwise and the reaction mixture was stirred at ambient temperature for about 20 h. The reaction mixture was slowly poured into stirred saturated aqueous NaHCO3 (1.5 L), followed by the portionwise addition of solid NaHCO3 (175 g). The mixture was stirred for about 2 h and the organic layer was separated, dried over anhydrous Na2SO4, and concd to dryness under reduced pressure. The crude yellow oil was purified by silica gel chromatography eluting with 0-20% EtOAc in heptane to yield ethyl 4-(dibenzylamino)-2-ethylcyclopentanecarboxylate (136.6 g, 72%) as a white solid: LC/MS (Table 1, Method a) Rt=3.26 min; MS m/z: 366 (M+H)+

Workup

  1. customresulting in formation of a thick suspension
  2. temperatureThe reaction mixture was warmed to about 10° C.
  3. additionThe reaction mixture was slowly poured
  4. stirringThe mixture was stirred for about 2 h
  5. customthe organic layer was separated
  6. dry with materialdried over anhydrous Na2SO4, and concd to dryness under reduced pressure
  7. customThe crude yellow oil was purified by silica gel chromatography
  8. washeluting with 0-20% EtOAc in heptane

Sources & evidence

ORD record
ord-5c0ddeb0b336498aa14642b2a90c4cc3
Source dataset
uspto-grants-2013_04
Patent number
US08426411B2

Reaction notes

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