Propionic anhydride → HCID 53922485, compound

HRID 1448739Notes

Reaction equation

HRID 1448739 reaction equation
[CH:1]1([NH:8][C:9](=[O:30])[C@@H:10]2[CH2:14][CH2:13][CH2:12][N:11]2[C:15](=[O:29])[C@H:16]([CH3:28])[NH:17][C:18]([O:20]CC2C=CC=CC=2)=O)[CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[C:31](OC(=O)CC)(=O)[CH2:32]C>Br.C(O)(=O)C.CCOCC>[CH:1]1([NH:8][C:9](=[O:30])[C@@H:10]2[CH2:14][CH2:13][CH2:12][N:11]2[C:15](=[O:29])[C@H:16]([CH3:28])[NH:17][C:18](=[O:20])[CH2:31][CH3:32])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7]1

Participants

6

Reactant 2

HCID 31263Propionic anhydrideHCID 54187700HCID 54187700, compound

Product 1

HCID 53922485HCID 53922485, compoundYield 88.1%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 260Hydrogen BromideSolventHCID 3283Diethyl EtherSolvent2×

Procedure

2.6 g (0.0063 mol) of N-benzyloxycarbonyl-L-alanyl-L-proline cycloheptylamide were dissolved in 15 ml of 4-N hydrogen bromide in acetic acid and the mixture was stirred at room temperature for 1 hour. 100 ml of anhydrous ether were added and an oil precipitated from the solution. The ether phase was decanted off and the oil washed with 100 ml of anhydrous ether. The ether layer was again decanted off and the oil dissolved in 30 ml of dry pyridine. 1.6 g (0.0126 mol) of propionic anhydride were added and the solution was stirred at room temperature for 2 hours. The pyridine was removed by evaporation, 50 ml of toluene were added to the residue and the mixture was again evaporated. The solid residue was taken up in 100 ml of chloroform and the solution was washed with sodium chloride solution and dried over magnesium sulphate. The chloroform was removed by evaporation to yield an oil. This oil was dissolved in the minimum volume of ether and petroleum ether was added, whereby a white solid crystallised out of the solution. There was obtained 1.85 g (88.1%) of N-propionyl-L-alanyl-L-proline cycloheptylamide of melting point 155°-156° C. [α]D20 =-119.4° (c=0.91% in methanol).

Workup

  1. customan oil precipitated from the solution
  2. customThe ether phase was decanted off
  3. washthe oil washed with 100 ml of anhydrous ether
  4. customThe ether layer was again decanted off
  5. dissolutionthe oil dissolved in 30 ml of dry pyridine
  6. stirringthe solution was stirred at room temperature for 2 hours
  7. customThe pyridine was removed by evaporation, 50 ml of toluene
  8. additionwere added to the residue
  9. customthe mixture was again evaporated
  10. washthe solution was washed with sodium chloride solution
  11. dry with materialdried over magnesium sulphate
  12. customThe chloroform was removed by evaporation
  13. customto yield an oil
  14. additionwas added
  15. customwhereby a white solid crystallised out of the solution

Sources & evidence

ORD record
ord-dcccc423b2d5481a8f28b53ac718dba8
Source dataset
uspto-grants-1980_02
Patent number
US04187216

Reaction notes

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