Isopropyl chloroformate → (2R)-2-(2,4-difluorophenyl)-2-[(3R,6R)-3-(2,3-dihydro-1H-inden-2-yl)-6-isobutyl-2,5-dioxopiperazin-1-yl]-N,N-dimethylethanamide

HRID 383967Notes

Reaction equation

HRID 383967 reaction equation
C(O[C:6]([NH:8][C@H:9]([CH:13]1[CH2:21][C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH2:14]1)[C:10]([OH:12])=O)=[O:7])(C)(C)C.CN1CCOCC1.C(OC(Cl)=O)(C)C.[F:36][C:37]1[CH:42]=[C:41]([F:43])[CH:40]=[CH:39][C:38]=1[CH:44]([NH:50][C@H:51](C(O)=O)[CH2:52][CH:53]([CH3:55])[CH3:54])[C:45]([N:47]([CH3:49])[CH3:48])=[O:46]>O1CCCC1.C1(C)C=CC=CC=1>[F:36][C:37]1[CH:42]=[C:41]([F:43])[CH:40]=[CH:39][C:38]=1[C@@H:44]([N:50]1[C@H:51]([CH2:52][CH:53]([CH3:55])[CH3:54])[C:6](=[O:7])[NH:8][C@H:9]([CH:13]2[CH2:14][C:15]3[C:20](=[CH:19][CH:18]=[CH:17][CH:16]=3)[CH2:21]2)[C:10]1=[O:12])[C:45]([N:47]([CH3:48])[CH3:49])=[O:46]

Participants

7

Reactant 4

HCID 7917Isopropyl chloroformateHCID 79724-MethylmorpholineHCID 11208543(R)-2-((tert-Butoxycarbonyl)amino)-2-(2,3-dihydro-1H-inden-2-yl)acetic acidHCID 68842051N-[1-(2,4-difluorophenyl)-2-(dimethylamino)-2-oxoethyl]-L-leucine

Product 1

HCID 11465834(2R)-2-(2,4-difluorophenyl)-2-[(3R,6R)-3-(2,3-dihydro-1H-inden-2-yl)-6-isobutyl-2,5-dioxopiperazin-1-yl]-N,N-dimethylethanamideYield 27.3%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of (2R)-[(tert-butoxycarbonyl)amino](2,3-dihydro-1H-inden-2-yl)ethanoic acid (84 mg) in dry tetrahydrofuran (6 ml) at −20° C. under a nitrogen atmosphere was added N-methylmorpholine (32 □l) and a solution of isopropylchloroformate in toluene (1.0M, 290 □l). After 10 minutes, a solution of N-[1-(2,4-difluorophenyl)-2-(dimethylamino)-2-oxoethyl]-L-leucine (95 mg) in tetrahydrofuran (10 ml) was added and the reaction was allowed to warm to room temperature. After 20 hours, the solvent was removed in vacuo and the residue was dissolved in 4N hydrochloric acid in dioxan (4 ml). After 4 hours methanol (5 ml) was added and the reaction was left to stand for a further 18 hours. The solvent was then removed in vacuo and the residue was dissolved in dioxan (5 ml) and to this was added triethylamine (0.5 ml). After 1 hour, the solvent was removed and the residue was applied to an SPE (10 g, silica). The product was eluted using methanol. A second SPE was used to further purify the material (2 g, silica) using an ethyl acetate: methanol gradient (20:1 to 1:1) to afford (2R)-2-(2,4-difluorophenyl)-2-[(3R,6R)-3-(2,3-dihydro-1H-inden-2-yl)-6-isobutyl-2,5-dioxopiperazin-1-yl]-N,N-dimethylethanamide (38 mg).

Workup

  1. waitAfter 20 hours
  2. customthe solvent was removed in vacuo
  3. dissolutionthe residue was dissolved in 4N hydrochloric acid in dioxan (4 ml)
  4. additionAfter 4 hours methanol (5 ml) was added
  5. waitthe reaction was left
  6. waitto stand for a further 18 hours
  7. customThe solvent was then removed in vacuo
  8. dissolutionthe residue was dissolved in dioxan (5 ml)
  9. additionto this was added triethylamine (0.5 ml)
  10. waitAfter 1 hour
  11. customthe solvent was removed
  12. washThe product was eluted
  13. customto further purify the material (2 g, silica)

Sources & evidence

ORD record
ord-d91f8840efac474badabc25d42ca757a
Source dataset
uspto-grants-2013_02
Patent number
US08367673B2

Reaction notes

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