Ethanol → tert-butyl (S)-4-[4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazin-1-yl]piperidine-1-carboxylate

HRID 856381Notes

Reaction equation

HRID 856381 reaction equation
Cl[C:2]1[N:3]([CH2:10][C@:11]2([CH3:14])[CH2:13][O:12]2)[CH:4]=[C:5]([N+:7]([O-:9])=[O:8])[N:6]=1.[N:15]1([CH:21]2[CH2:26][CH2:25][N:24]([C:27]([O:29][C:30]([CH3:33])([CH3:32])[CH3:31])=[O:28])[CH2:23][CH2:22]2)[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1.C(O)C.[H-].[Na+]>CN(C)C=O.O.C(OCC)(=O)C>[CH3:14][C@@:11]1([CH2:13][N:18]2[CH2:19][CH2:20][N:15]([CH:21]3[CH2:22][CH2:23][N:24]([C:27]([O:29][C:30]([CH3:33])([CH3:32])[CH3:31])=[O:28])[CH2:25][CH2:26]3)[CH2:16][CH2:17]2)[O:12][C:2]2=[N:6][C:5]([N+:7]([O-:9])=[O:8])=[CH:4][N:3]2[CH2:10]1

Participants

8

Reactant 4

HCID 702EthanolHCID 24758Sodium hydrideHCID 10443353(R)-2-chloro-1-(2-methyloxiran-2-ylmethyl)-4-nitroimidazoleHCID 17750358tert-Butyl 4-(piperazin-1-yl)piperidine-1-carboxylate

Product 1

HCID 69635208tert-butyl (S)-4-[4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazin-1-yl]piperidine-1-carboxylateYield 66%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
50 °C

Procedure

A mixture of (R)-2-chloro-4-nitro-1-(2-methyl-2-oxiranylmethyl)imidazole (3 g, 13.79 mmol), tert-butyl 4-piperazin-1-yl-piperidine-1-carboxylate (3.9 g, 14.48 mmol), and ethanol (30 ml) was stirred at 50° C. for 9 hours. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography (methylene chloride/methanol=10/1) to obtain a yellow amorphous form. The amorphous form was dissolved in N,N-dimethylformamide (18 ml), sodium hydride (651 mg, 16.28 mmol) was added while cooling on ice, and the resultant solution was stirred at the same temperature for 1 hour. To the reaction mixture, ethyl acetate (6 ml) and water (42 ml) were added in this order, and the precipitated crystals were filtered off and washed with water. The filtrate was recrystallized from 2-propanol (20 ml)/water (60 ml) to obtain tert-butyl (S)-4-[4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazin-1-yl]piperidine-1-carboxylate (4.08 g, 66%) as a light yellow powder.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. customthe residue was purified by silica gel column chromatography (methylene chloride/methanol=10/1)
  3. customto obtain a yellow amorphous form
  4. temperaturewhile cooling on ice
  5. filtrationthe precipitated crystals were filtered off
  6. washwashed with water
  7. customThe filtrate was recrystallized from 2-propanol (20 ml)/water (60 ml)

Sources & evidence

ORD record
ord-9705b1a39a87474e87242b43afb0857c
Source dataset
uspto-grants-2007_08
Patent number
US07262212B2

Reaction notes

Loading…