Trifluoroacetic acid → benzyl N-methyl-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamate

HRID 856249Notes

Reaction equation

HRID 856249 reaction equation
[CH3:1][N:2]([CH:10]1[CH2:15][CH2:14][N:13]([CH2:16][C:17]2([CH3:28])[O:21][C:20]3=[N:22][C:23]([N+:25]([O-:27])=[O:26])=[CH:24][N:19]3[CH2:18]2)[CH2:12][CH2:11]1)[C:3](=[O:9])[O:4]C(C)(C)C.FC(F)(F)C(O)=O.C(N(CC)CC)C.C(Cl)(=O)O[CH2:45][C:46]1[CH:51]=[CH:50][CH:49]=[CH:48][CH:47]=1>C(Cl)Cl.O>[CH3:1][N:2]([CH:10]1[CH2:15][CH2:14][N:13]([CH2:16][C:17]2([CH3:28])[O:21][C:20]3=[N:22][C:23]([N+:25]([O-:27])=[O:26])=[CH:24][N:19]3[CH2:18]2)[CH2:12][CH2:11]1)[C:3](=[O:9])[O:4][CH2:45][C:46]1[CH:51]=[CH:50][CH:49]=[CH:48][CH:47]=1

Participants

7

Reactant 4

HCID 6422Trifluoroacetic acidHCID 8471TriethylamineHCID 10387Benzyl chloroformateHCID 23081148HCID 23081148, compound

Product 1

HCID 69482026benzyl N-methyl-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamateYield 82.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Procedure

Tert-butyl N-methyl-{1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl}carbamate prepared in Example 236 (207 mg, 0.52 mmol) was dissolved in methylene chloride (5 ml). To the solution, trifluoroacetic acid (5 ml) was added followed by stirring at room temperature for 5 hours. The reaction mixture was concentrated under reduced pressure. To the residue, methylene chloride (5 ml), triethylamine (1 ml) and benzyl chlorocarbonate (0.15 ml, 1.05 mmol) were added followed by stirring at room temperature for 30 minutes. The reaction mixture was poured into water, extracted with methylene chloride. The organic phase was dried over sodium sulfate and then filtered. The resulting filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/methanol=200/1) and crystallized from ethyl acetate-isopropyl ether to afford benzyl N-methyl-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamate (184 mg, yield 82%) as a white powder.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure
  2. stirringby stirring at room temperature for 30 minutes
  3. extractionextracted with methylene chloride
  4. dry with materialThe organic phase was dried over sodium sulfate
  5. filtrationfiltered
  6. concentrationThe resulting filtrate was concentrated under reduced pressure
  7. customThe residue was purified by silica gel column chromatography (methylene chloride/methanol=200/1)
  8. customcrystallized from ethyl acetate-isopropyl ether

Sources & evidence

ORD record
ord-aebee42e664e435196f416a877c520c4
Source dataset
uspto-grants-2007_08
Patent number
US07262212B2

Reaction notes

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