Trifluoroacetic acid → 5-(2-Diethylamino-ethyl)-3-methyl-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carbaldehyde

HRID 2191400Notes

Reaction equation

HRID 2191400 reaction equation
C([O:5][C:6]([C:8]1[NH:17][C:16]2[CH2:15][CH2:14][CH2:13][N:12]([CH2:18][CH2:19][N:20]([CH2:23][CH3:24])[CH2:21][CH3:22])[C:11](=[O:25])[C:10]=2[C:9]=1[CH3:26])=O)(C)(C)C.FC(F)(F)C(O)=O.C(OC(OCC)OCC)C>>[CH2:23]([N:20]([CH2:21][CH3:22])[CH2:19][CH2:18][N:12]1[CH2:13][CH2:14][CH2:15][C:16]2[NH:17][C:8]([CH:6]=[O:5])=[C:9]([CH3:26])[C:10]=2[C:11]1=[O:25])[CH3:24]

Participants

4

Reactant 3

HCID 6422Trifluoroacetic acidHCID 31214Ethyl orthoformateHCID 498403955-(2-Diethylamino-ethyl)-3-methyl-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carboxylic acid tert-butyl ester

Product 1

HCID 592500815-(2-Diethylamino-ethyl)-3-methyl-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carbaldehydeYield 81.6%

Conditions

Temperature
40 °C

Procedure

5-(2-Diethylamino-ethyl)-3-methyl-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carboxylic acid tert-butyl ester 1i (0.413 g, 1.14 mmol) was dissolved in trifluoroacetic acid (1.5 ml, 20 mmol) under stirring, heated to 40° C. for 5 minutes in an oil bath under an argon atmosphere, and cooled down to −5° C. in an ice-salt bath under stirring, and added with triethoxy methane (0.34 ml, 1.7 mmol) and stirred for 2 minutes. Then the ice-salt bath was removed, and the reaction mixture was allowed to warm up to room temperature and stirred for another about 2 hours. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was added with 3 ml of ice water and 10 ml of dichloromethane, adjusted to pH 11 with aqueous sodium hydroxide solution (2 mol/L) and extracted with dichloromethane (10 ml×3). The combined organic extracts were dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure to obtain yellow oil. The residue was purified by silica gel column chromatography to obtain the title compound 5-(2-diethylamino-ethyl)-3-methyl-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carbaldehyde 1j (0.271 g, yield 55%) as a light brown oil.

Workup

  1. temperaturecooled down to −5° C. in an ice-salt bath
  2. stirringunder stirring
  3. stirringstirred for 2 minutes
  4. customThen the ice-salt bath was removed
  5. temperatureto warm up to room temperature
  6. stirringstirred for another about 2 hours
  7. additionthe reaction mixture was added with 3 ml of ice water and 10 ml of dichloromethane
  8. extractionextracted with dichloromethane (10 ml×3)
  9. dry with materialThe combined organic extracts were dried over anhydrous magnesium sulfate
  10. filtrationfiltered
  11. customto remove the drying agent
  12. concentrationconcentrated under reduced pressure
  13. customto obtain yellow oil
  14. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-5c2329fe87fa4aa69f2d1969394274d7
Source dataset
uspto-grants-2012_12
Patent number
US08329682B2

Reaction notes

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