L-Isoleucine → N-[2(S)-[t-butoxycarbonylamino]-3-methylpentyl]-isoleucine

HRID 964741Notes

Reaction equation

HRID 964741 reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[C@H:3]([CH2:5][CH3:6])[CH3:4].FC(F)(F)C(O)=O.[C:17]([O:21][C:22]([NH:24][C@H:25]([CH:30]=O)[C@H:26]([CH2:28][CH3:29])[CH3:27])=[O:23])([CH3:20])([CH3:19])[CH3:18].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>CO.CN(C=O)C>[C:17]([O:21][C:22]([NH:24][C@@H:25]([CH:26]([CH3:27])[CH2:28][CH3:29])[CH2:30][NH:1][C@H:2]([C:7]([OH:9])=[O:8])[C@H:3]([CH2:5][CH3:6])[CH3:4])=[O:23])([CH3:19])([CH3:20])[CH3:18]

Participants

7

Reactant 4

HCID 6306L-Isoleucine2×HCID 6422Trifluoroacetic acidHCID 5049666Sodium triacetoxyborohydrideHCID 113902721,1-Dimethylethyl N-((1S,2S)-1-formyl-2-methylbutyl)carbamate

Product 1

HCID 18661137N-[2(S)-[t-butoxycarbonylamino]-3-methylpentyl]-isoleucineYield 84%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6228DimethylformamideSolvent

Procedure

Isoleucine (1.31 g, 9.95 mmol) was suspended in anhydrous methanol (10 ml) and trifluoroacetic acid (1.133 g, 0.77 ml, 9.95 mmol) was added. The mixture was stirred until all the isoleucine had dissolved and the solvent was then removed under reduced pressure. Anhydrous DMF (10 ml) was added to the resulting isoleucine trifluoroacetate salt followed by 3 Å molecular sieves and a solution of 2 (1.47 g, 4.9 mmol) in anhydrous DMF (5 ml). After 15 minutes the solution was treated with sodium triacetoxy borohydride (1.58 g, 7.45 mmol) and stirred overnight. The resulting suspension was filtered through celite, diluted with ethyl acetate (50 ml) and washed with saturated sodium chloride solution (2×35 ml). The organic extracts were dried over magnesium sulfate, filtered, and the solvent removed under reduced pressure to yield the acid (1.36 g, 84%) as a yellow oil.

Workup

  1. dissolutionhad dissolved
  2. customthe solvent was then removed under reduced pressure
  3. additionAnhydrous DMF (10 ml) was added to the resulting isoleucine trifluoroacetate salt
  4. filtrationThe resulting suspension was filtered through celite
  5. additiondiluted with ethyl acetate (50 ml)
  6. washwashed with saturated sodium chloride solution (2×35 ml)
  7. dry with materialThe organic extracts were dried over magnesium sulfate
  8. filtrationfiltered
  9. customthe solvent removed under reduced pressure

Sources & evidence

ORD record
ord-6a4c932476374c9ba5911767b2500bc3
Source dataset
uspto-grants-1998_06
Patent number
US05770731

Reaction notes

Loading…