Hydrochloric Acid → Dimethyl 1-(2-chloroethyl)cyclohexane-1,4-dicarboxylate

HRID 2280737Notes

Reaction equation

HRID 2280737 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[CH:13]1([C:23]([O:25][CH3:26])=[O:24])[CH2:18][CH2:17][CH:16]([C:19]([O:21][CH3:22])=[O:20])[CH2:15][CH2:14]1.CN(C)P(N(C)C)(N(C)C)=O.C(NC(C)C)(C)C.[Li].Br[CH2:47][CH2:48][Cl:49].Cl>C1COCC1>[Cl:49][CH2:48][CH2:47][C:16]1([C:19]([O:21][CH3:22])=[O:20])[CH2:15][CH2:14][CH:13]([C:23]([O:25][CH3:26])=[O:24])[CH2:18][CH2:17]1

Participants

9

Reactant 7

HCID 313Hydrochloric AcidHCID 7198Dimethyl 1,4-cyclohexanedicarboxylateHCID 78491-Bromo-2-ChloroethaneHCID 7912DiisopropylamineHCID 12679HexamethylphosphoramideHCID 45051747Lithium diisopropylamineHCID 178418339Butyllithium

Product 1

HCID 13633965Dimethyl 1-(2-chloroethyl)cyclohexane-1,4-dicarboxylateYield 88.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

To a solution of diisopropylamine (88 mL, 0.62 mol) in anhydrous THF (500 mL) was added n-butyl lithium (240 mL, 0.6 mol, 2.5 M solution in hexane) over 20 minutes at −78° C. The mixture was stirred at 0° C. under nitrogen for 30 min. To a mixture of dimethyl cyclohexane-1,4-dicarboxylate (100 g, 0.5 mol) and hexamethylphosphoramide (360 mL, 2 mol) in anhydrous THF (800 mL) was added lithium diisopropylamine (freshly prepared above) over 30 min at −40° C. After stirring for 1 h at this temperature, 1-bromo-2-chloroethane (42 mL, 0.5 mol) was added over 1 h. The mixture was stirred for 3 h at −78° C., then warmed to room temperature and stirred overnight. To the reaction mixture was added aqueous hydrochloric acid (3 N, 420 mL) and the mixture was stirred for 10 min. The solvent was removed by evaporation under reduced pressure. The aqueous layer was extracted with ethyl acetate (3×200 mL), and the combined extracts were washed with brine (2×300 mL) and dried over sodium sulfate. Concentration under reduced pressure afforded dimethyl 1-(2-chloroethyl)cyclohexane-1,4-dicarboxylate (116 g, 88% yield), which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 3.72 (s, 3H), 3.65 (s, 3H), 3.46-3.42 (m, 2H), 2.33-2.21 (m, 3H), 2.05-1.85 (m, 4H), 1.58-1.42 (m, 2H), 1.25-1.15 (m, 2H).

Workup

  1. customfreshly prepared above) over 30 min at −40° C
  2. additionwas added over 1 h
  3. stirringThe mixture was stirred for 3 h at −78° C.
  4. temperaturewarmed to room temperature
  5. stirringstirred overnight
  6. stirringthe mixture was stirred for 10 min
  7. customThe solvent was removed by evaporation under reduced pressure
  8. extractionThe aqueous layer was extracted with ethyl acetate (3×200 mL)
  9. washthe combined extracts were washed with brine (2×300 mL)
  10. dry with materialdried over sodium sulfate
  11. concentrationConcentration under reduced pressure

Sources & evidence

ORD record
ord-f63c62da9ab84b76ac3f3ff371089289
Source dataset
uspto-grants-2015_09
Patent number
US09139534B2

Reaction notes

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