Propionic anhydride → HCID 53724444, compound

HRID 1448741Notes

Reaction equation

HRID 1448741 reaction equation
[CH:1]1([NH:9][C:10](=[O:31])[C@@H:11]2[CH2:15][CH2:14][CH2:13][N:12]2[C:16](=[O:30])[C@H:17]([CH3:29])[NH:18][C:19]([O:21]CC2C=CC=CC=2)=O)[CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[C:32](OC(=O)CC)(=O)[CH2:33]C>Br.C(O)(=O)C.C(Cl)(Cl)Cl.CCOCC>[CH:1]1([NH:9][C:10](=[O:31])[C@@H:11]2[CH2:15][CH2:14][CH2:13][N:12]2[C:16](=[O:30])[C@H:17]([CH3:29])[NH:18][C:19](=[O:21])[CH2:32][CH3:33])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8]1

Participants

7

Reactant 2

HCID 31263Propionic anhydrideHCID 53872165HCID 53872165, compound

Product 1

HCID 53724444HCID 53724444, compoundYield 56.3%

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 260Hydrogen BromideSolventHCID 3283Diethyl EtherSolvent2×HCID 6212ChloroformSolvent

Procedure

2 g (0.0047 mol) of N-benzyloxycarbonyl-L-alanyl-L-proline cyclooctylamide were dissolved in 10 ml of 4-N hydrogen bromide in acetic acid and the solution was stirred at room temperature for 1 hour. 100 ml of anhydrous ether were added and an oil precipitated out of the solution. The ether layer 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. 1.2 g (0.0094 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 in order to azeotropically remove any residual pyridine. The solid obtained was taken up in 100 ml of chloroform, the solution was washed with sodium chloride solution and dried over magnesium sulphate. The solution was then evaporated 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 0.900 g (56.3%) of N-propionyl-L-alanyl-L-proline cyclooctylamide of melting point 142°-143° C.; [α]D20 =-120.3° (c=0.82% in methanol).

Workup

  1. customan oil precipitated out of the solution
  2. customThe ether layer 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 in order
  10. customto azeotropically remove any residual pyridine
  11. customThe solid obtained
  12. washthe solution was washed with sodium chloride solution
  13. dry with materialdried over magnesium sulphate
  14. customThe solution was then evaporated
  15. customto yield an oil
  16. additionwas added
  17. customwhereby a white solid crystallised out of the solution

Sources & evidence

ORD record
ord-2f5211178a56413980f1309208423f86
Source dataset
uspto-grants-1980_02
Patent number
US04187216

Reaction notes

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