Iodine → 1-(t-butoxycarbonyl)-4(N-acetyl-L-methionyl)piperazine

HRID 843496

Reaction equation

HRID 843496 reaction equation
[C:1]([NH:4][C@H:5]([C:10]([OH:12])=O)[CH2:6][CH2:7][S:8][CH3:9])(=[O:3])[CH3:2].C1(N=C=NC2CCCCC2)CCCCC1.[C:28]([O:32][C:33]([N:35]1[CH2:40][CH2:39][NH:38][CH2:37][CH2:36]1)=[O:34])([CH3:31])([CH3:30])[CH3:29].II.C1C=C2C(C(O)(O)C(=O)C2=CC=1)=O>C(Cl)Cl.C(O)(=O)C.O1CCCC1.C(#N)C>[C:28]([O:32][C:33]([N:35]1[CH2:40][CH2:39][N:38]([C:10](=[O:12])[C@H:5]([CH2:6][CH2:7][S:8][CH3:9])[NH:4][C:1](=[O:3])[CH3:2])[CH2:37][CH2:36]1)=[O:34])([CH3:31])([CH3:29])[CH3:30]

Participants

10

Reactant 5

HCID 807IodineHCID 10236NinhydrinHCID 10868DicyclohexylcarbodiimideHCID 143452tert-Butyl piperazine-1-carboxylateHCID 448580N-acetyl-L-methionine

Product 1

HCID 544692851-(t-butoxycarbonyl)-4(N-acetyl-L-methionyl)piperazineYield 108.6%

Reagents, catalysts & solvents 4

HCID 176Acetic AcidCatalystHCID 6342AcetonitrileSolvent2×HCID 6344DichloromethaneSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 4.78 g (0.025 mol) of N-acetyl-L-methionine in CH2Cl2: acetonitrile (120 ml) was cooled to 0° C. To this solution was added 5.36 g (0.025 mol) of dicyclohexylcarbodiimide (DCC) followed by the rapid addition of 3.90 g (0.021 mol) of N-t-butoxycarbonylpiperazine in 6 ml of dichloromethane. The progress of the reaction was followed on silica gel TLC plates developed with 4:1 acetonitrile: tetrahydrofuran and visualized with either iodine or ninhydrin spray. The reaction was complete within 2 h. A few drops of glacial acetic acid were added to the reaction mixture and the solvent was removed on a rotary evaporator. The residue was taken up in ether and filtered. The clear filtrate was washed with dilute acid followed by dilute base. The organic layer was separated, dried over anhydrous sodium sulfate, filtered, and evaporated to give 8.2 g of 1-(t-butoxycarbonyl)-4-(N-acetyl-L-methionyl)piperazine, a colorless oil which required no further purification: IR (film) 3304, 3058, 2973, 2931, 2868, 1701, 1645, 1539, 1420, 1237, 1173 cm−1; NMR (CDCl3) δ 1.47 (s, 9 H), 1.80 (m, 2 H), 2.02 (s, 3 H), 2.10 (s, 3 H), 2.46 (m, 2 H), 3.53 (m, 8 H), 5.10 (M, 1 H), 6.35 (b, 0.5 H), 6.43 (b, 0.5 H).

Workup

  1. customthe solvent was removed on a rotary evaporator
  2. filtrationfiltered
  3. washThe clear filtrate was washed
  4. additionwith dilute acid
  5. additionby dilute base
  6. customThe organic layer was separated
  7. dry with materialdried over anhydrous sodium sulfate
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-e9f2ee3fd26a41dca19b2fd7f0ca7cce
Source dataset
uspto-grants-2002_04
Patent number
US06379660B1

Linked notes

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