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

HRID 1969748Notes

Reaction equation

HRID 1969748 reaction equation
[CH3:1][CH:2]1[CH2:6][C:5](=O)[CH2:4][CH:3]1[C:8]([O:10][CH2:11][CH3:12])=[O:9].CC(O)=O.[CH2:17]([NH:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C([O-])(O)=O.[Na+]>ClCCCl>[CH2:25]([N:24]([CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)[CH:5]1[CH2:4][CH:3]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:2]([CH3:1])[CH2:6]1)[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 7656DibenzylamineHCID 516892Sodium BicarbonateHCID 5049666Sodium triacetoxyborohydrideHCID 13089479Ethyl 2-methyl-4-oxocyclopentanecarboxylate

Product 1

HCID 58010318Ethyl 4-(dibenzylamino)-2-methylcyclopentanecarboxylateYield 75%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
0 °C

Procedure

A round bottom flask was charged with ethyl 2-methyl-4-oxocyclopentanecarboxylate (10.0 g, 58.8 mmol) and DCE (180 mL). The solution was cooled to about 0° C. and AcOH (5.7 mL, 100 mmol) and dibenzylamine (11.3 mL, 58.8 mmol) were added dropwise, resulting in formation of a thick suspension. The reaction mixture was warmed to about 10° C. and sodium triacetoxyborohydride (21.2 g, 100 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 (300 mL) and was stirred for about 20 min. The layers were separated and the aqueous phase was extracted with DCM (3×100 mL). The combined organic extracts were washed with brine (2×100 mL), dried over anhydrous Na2SO4, and concd under reduced pressure. The crude yellow oil was purified via flash column chromatography eluting with a gradient of 0-30% EtOAc in heptane to give ethyl 4-(dibenzylamino)-2-methylcyclopentanecarboxylate (15.5 g, 75%) as a colorless oil: 1H NMR (pyridine-d5) δ 7.53 (dd, J=0.9, 7.9 Hz, 4H), 7.43-7.35 (m, 4H), 7.33-7.25 (m, 2H), 4.22-4.06 (m, 2H), 3.79 (d, J=14.2 Hz, 2H), 3.70 (d, J=14.2 Hz, 2H), 3.34-3.22 (m, 1H), 2.76 (dd, J=7.9, 16.6 Hz, 1H), 2.25-2.13 (m, 1H), 2.09-1.94 (m, 2H), 1.88-1.79 (m, 1H), 1.52 (dd, J=10.5, 22.5 Hz, 1H), 1.16 (t, J=7.1 Hz, 3H), 0.98 (d, J=7.0 Hz, 3H).

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. stirringwas stirred for about 20 min
  5. customThe layers were separated
  6. extractionthe aqueous phase was extracted with DCM (3×100 mL)
  7. washThe combined organic extracts were washed with brine (2×100 mL)
  8. dry with materialdried over anhydrous Na2SO4, and concd under reduced pressure
  9. customThe crude yellow oil was purified via flash column chromatography
  10. washeluting with a gradient of 0-30% EtOAc in heptane

Sources & evidence

ORD record
ord-ded03c14ddb84ba8b9e25a7b920b6426
Source dataset
uspto-grants-2013_04
Patent number
US08426411B2

Reaction notes

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