Water → Methyl 2-bromo-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine-7-carboxylate

HRID 874343Notes

Reaction equation

HRID 874343 reaction equation
O1CCCC1.[Br:6][C:7]1[N:8]=[C:9]2[CH2:14][CH:13]([C:15]([O:17][CH3:18])=[O:16])[CH2:12][CH2:11][N:10]2[C:19]=1Br.C([Mg]Br)(C)C.O>C(OCC)(=O)C>[Br:6][C:7]1[N:8]=[C:9]2[CH2:14][CH:13]([C:15]([O:17][CH3:18])=[O:16])[CH2:12][CH2:11][N:10]2[CH:19]=1

Participants

6

Reactant 4

HCID 962WaterHCID 8028TetrahydrofuranHCID 90383288Methyl 2,3-dibromo-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine-7-carboxylateHCID 178418365HCID 178418365, compound

Product 1

HCID 90383213Methyl 2-bromo-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine-7-carboxylateYield 68.2%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-35 °C

Procedure

A tetrahydrofuran (150 ml) solution of the methyl 2,3-dibromo-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine-7-carboxylate (13 g) obtained in (Example 2.7) <Step 1> was cooled to −35° C. Thereafter, isopropylmagnesium bromide (95 ml, 1 M tetrahydrofuran solution) was added to the solution over 20 minutes, while keeping the temperature at −30° C. or less, and the reaction solution was then stirred at −35° C. for 30 minutes. Thereafter, water (350 ml) and ethyl acetate (250 ml) were added to the reaction solution, and insoluble matters were then removed by filtration with Celite. Subsequently, the filtrate was separated into an organic layer and a water layer. The water layer was extracted with ethyl acetate (250 ml), and the organic layers were then gathered. The gathered organic layer was washed with a saturated saline, and the solvent was then distilled away under reduced pressure. The obtained residue was purified by silica gel column chromatography (silica gel:eluent; heptane:ethyl acetate=70:30-30:70), so as to obtain the title compound (6.8 g) in the form of a white solid.

Workup

  1. customat −30° C. or less
  2. customwere then removed by filtration with Celite
  3. customSubsequently, the filtrate was separated into an organic layer
  4. extractionThe water layer was extracted with ethyl acetate (250 ml)
  5. washThe gathered organic layer was washed with a saturated saline
  6. distillationthe solvent was then distilled away under reduced pressure
  7. customThe obtained residue was purified by silica gel column chromatography (silica gel:eluent; heptane:ethyl acetate=70:30-30:70)

Sources & evidence

ORD record
ord-85ba2d5711314990b7805c09417a63a5
Source dataset
uspto-grants-2015_03
Patent number
US08980888B2

Reaction notes

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