Ethyl chloroformate → Ethyl 1-ethoxycarbonyl-1,2,3,6-tetrahydropyridine-4-carboxylate

HRID 2182055Notes

Reaction equation

HRID 2182055 reaction equation
C[N:2]1[CH2:7][CH:6]=[C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH2:4][CH2:3]1.C(N(C(C)C)CC)(C)C.Cl[C:23]([O:25][CH2:26][CH3:27])=[O:24].C(=O)([O-])O.[Na+]>C1C=CC=CC=1>[CH2:26]([O:25][C:23]([N:2]1[CH2:3][CH:4]=[C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH2:6][CH2:7]1)=[O:24])[CH3:27]

Participants

6

Reactant 4

HCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 516892Sodium BicarbonateHCID 566021Ethyl 1-methyl-1,2,3,6-tetrahydro-4-pyridinecarboxylate

Product 1

HCID 12549670Ethyl 1-ethoxycarbonyl-1,2,3,6-tetrahydropyridine-4-carboxylateYield 71.4%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

In 640 ml of benzene, 108.9 g of ethyl 1-methyl-1,2,3,6-tetrahydropyridine-4-carboxylate and 41.6 g of diisopropylethylamine were dissolved, and subsequently, 279.1 g of ethyl chloroformate was added dropwise thereto over 70 minutes. The reaction mixture was heated under reflux for 30 minutes, followed by cooling the reaction mixture to room temperature. A saturated aqueous solution of sodium hydrogencarbonate was poured thereinto. After the reaction mixture was extracted with ethyl acetate, the extract was washed with saturated brine and was then dried over anhydrous sodium sulfate. The desiccant was filtered off, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=7:1) to yield 104.4 g of ethyl 1-ethoxycarbonyl-1,2,3,6-tetrahydropyridine-4-carboxylate as an oil.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 30 minutes
  3. extractionAfter the reaction mixture was extracted with ethyl acetate
  4. washthe extract was washed with saturated brine
  5. dry with materialwas then dried over anhydrous sodium sulfate
  6. filtrationThe desiccant was filtered off
  7. concentrationthe filtrate was concentrated under reduced pressure
  8. customThe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=7:1)

Sources & evidence

ORD record
ord-1eea4bb1f8bd46cba265c357db796725
Source dataset
uspto-grants-2005_05
Patent number
US06894168B2

Reaction notes

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