Acetic Acid → BOC-Leu-Ser-Thr-OBzl

HRID 971579

Reaction equation

HRID 971579 reaction equation
[NH2:1][C@H:2]([C:5]([NH:7][C@H:8]([C:12]([O:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[O:13])[C@@H:9]([CH3:11])[OH:10])=[O:6])[CH2:3][OH:4].FC(C(O)=O)(F)F.[CH3:29][CH:30]([CH2:32][C@H:33]([NH:46][C:47]([O:49][C:50]([CH3:53])([CH3:52])[CH3:51])=[O:48])[C:34](OC1C=CC([N+]([O-])=O)=CC=1)=[O:35])[CH3:31].C(N(CC)CC)C.C(O)(=O)C>CN(C)C=O.C(OCC)(=O)C>[NH:46]([C:47]([O:49][C:50]([CH3:52])([CH3:51])[CH3:53])=[O:48])[C@H:33]([C:34]([NH:1][C@H:2]([C:5]([NH:7][C@H:8]([C:12]([O:14][CH2:15][C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1)=[O:13])[C@@H:9]([CH3:11])[OH:10])=[O:6])[CH2:3][OH:4])=[O:35])[CH2:32][CH:30]([CH3:31])[CH3:29]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 8471TriethylamineHCID 1810201N-[(1,1-Dimethylethoxy)carbonyl]-L-leucine 4-nitrophenyl esterHCID 131711572H-Ser-Thr-OBzl.TFA

Product 1

HCID 131711574BOC-Leu-Ser-Thr-OBzl

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

52.5 g of H-Ser-Thr-OBzl.TFA are dissolved in 145 ml of dimethylformamide and mixed at 0° C. with a solution of 48.0 g of BOC-Leu-ONP. 21 ml of triethylamine and 0.75 ml of glacial acetic acid are then added. The reaction mixture is stirred for 3 hours at 0° C. and overnight at room temperature. After adding 2.1 liters of ethyl acetate the solution is extracted by shaking twice with water, twice with 0.1 N hydrochloric acid, twice with 10% strength sodium chloride solution, eight times with 20% strength potassium carbonate solution, twice with 10% strength sodium chloride solution and once with 30% strength sodium chloride solution. After drying over sodium sulphate the solution is concentrated to about 1.4 liters. The protected tripeptide of melting point 114°-116° C. crystallises overnight in the refrigerator; [α]D -14° (c = 2 in dimethylformamide); Rf2 = 0.25 (on silica gel).

Workup

  1. extractionis extracted
  2. stirringby shaking twice with water, twice with 0.1 N hydrochloric acid, twice with 10% strength sodium chloride solution, eight times with 20% strength potassium carbonate solution, twice with 10% strength sodium chloride solution and once with 30% strength sodium chloride solution
  3. dry with materialAfter drying over sodium sulphate the solution
  4. concentrationis concentrated to about 1.4 liters
  5. customThe protected tripeptide of melting point 114°-116° C. crystallises overnight in the refrigerator

Sources & evidence

ORD record
ord-cf4850c7610342bca7e023d4ebac8c36
Source dataset
uspto-grants-1979_07
Patent number
US04159981

Linked notes

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