Isobutyl chloroformate → Boc-Ile-Pro-OBzl

HRID 1741980Notes

Reaction equation

[NH:1]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C@H:2]([C:7]([OH:9])=O)[C@H:3]([CH2:5][CH3:6])[CH3:4].C(OC(Cl)=O)C(C)C.C1C=CC2N(O)N=NC=2C=1.Cl.[NH:36]1[CH2:50][CH2:49][CH2:48][C@H:37]1[C:38]([O:40][CH2:41][C:42]1[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1)=[O:39].C([O-])(O)=O.[Na+]>CN(C=O)C.CN1CCOCC1>[NH:1]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C@H:2]([C:7]([N:36]1[CH2:50][CH2:49][CH2:48][C@H:37]1[C:38]([O:40][CH2:41][C:42]1[CH:43]=[CH:44][CH:45]=[CH:46][CH:47]=1)=[O:39])=[O:9])[C@H:3]([CH2:5][CH3:6])[CH3:4]

Participants

Conditions

Temperature: -15 °C

Procedure

Boc-Ile-OH (12.01 g. 0.05 mole) in DMF (50 ml) was cooled to 0° C. and NMM (5.49 ml) was added. After cooling the solution to -15° C. isobutylchloroformate (6.48 ml) was added slowly while maintaining the temperature at -15° C. and stirred for 10 minutes at which time HOBt (7.65 g) was added and stirring was continued for additional 10 minutes. A pre-cooled solution of HCl-H-Pro-OBzl (12.09 g. 0.05 mole) in DMF (50 ml) and NMM (5.49 ml) was added to the above solution and the completeness of the reaction was followed by TLC. The reaction mixture was poured into a cold saturated NaHCO3 solution and stirred for one hour. The peptide was extracted into CHCl3 and washed with acid and base (0.5N NaOH to remove HOBt), and on evaporting the solvent the product was obtained as an oil in 92% yield. Rf1, 0.65. Anal. Calcd. for C23H34N2O5 : C 66.00, H 9.19, N 6.69%. Found: C 65.58, H 8.28, N 7.13%.

Workup

additionwas added slowly
additionwas added
stirringstirred for one hour
extractionThe peptide was extracted into CHCl3
washwashed with acid and base (0.5N NaOH to remove HOBt)
customwas obtained as an oil in 92% yield

Sources & evidence

ORD record: ord-9154a334eda441bc82897c4dd646bc4b
Source dataset: uspto-grants-1994_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05336256

Reaction notes

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