Ethyl chloroformate → HCID 68532344, compound

HRID 1379736Notes

Reaction equation

HRID 1379736 reaction equation
C([N-]C(C)C)(C)C.[Li+].[CH2:9]([O:11][C:12]([CH:14]1[CH2:26][CH2:25][N:17]2[C:18]3[C:23]([CH:24]=[C:16]2[CH2:15]1)=[CH:22][CH:21]=[CH:20][CH:19]=3)=[O:13])[CH3:10].Cl[C:28]([O:30][CH2:31][CH3:32])=[O:29]>C1COCC1>[CH2:9]([O:11][C:12]([C:14]1([C:28]([O:30][CH2:31][CH3:32])=[O:29])[CH2:26][CH2:25][N:17]2[C:18]3[C:23]([CH:24]=[C:16]2[CH2:15]1)=[CH:22][CH:21]=[CH:20][CH:19]=3)=[O:13])[CH3:10]

Participants

5

Reactant 3

HCID 10928Ethyl chloroformateHCID 2724682Lithium diisopropylamideHCID 15063389HCID 15063389, compound

Product 1

HCID 68532344HCID 68532344, compoundYield 33%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a -78° C. THF (12 mL) solution of lithium diisopropylamide (generated in situ from diisopropylamine (3.8 mL) and 15% n-butyl lithium in hexane (17 mL) at 0° C.) was added dropwise a THF solution of 6,7,8,9-tetrahydropyrido[1,2-a]indole-8-carboxylic acid ethyl ester. After 30 minutes, the temperature was brought to 0° C. After 1 hour, ethyl chloroformate (2.6 mL) was added over one hour. The reaction was allowed to come to room temperature overnight. The reaction was quenched with saturated NH4Cl and extracted t-butyl methyl ether (3×). The extract was washed with water, dried, filtered, and concentrated to give a residue. The residue was purified by flash chromatography eluting with 15% ethyl acetate/hexane to give the title compound 1.29 g (33% yield) as off white crystals (M.Pt. 69° C.).

Workup

  1. customTo a -78° C
  2. customwas brought to 0° C
  3. waitAfter 1 hour
  4. waitto come to room temperature overnight
  5. customThe reaction was quenched with saturated NH4Cl
  6. extractionextracted t-butyl methyl ether (3×)
  7. washThe extract was washed with water
  8. customdried
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customto give a residue
  12. customThe residue was purified by flash chromatography
  13. washeluting with 15% ethyl acetate/hexane

Sources & evidence

ORD record
ord-a176572e6454403d8293d22b09a3b39b
Source dataset
uspto-grants-1997_09
Patent number
US05672618

Reaction notes

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