Potassium Carbonate → 5-Ethynylpyridin-2-amine

HRID 269080Notes

Reaction equation

HRID 269080 reaction equation
C[Si]([C:5]#[C:6][C:7]1[CH:8]=[CH:9][C:10]([NH2:13])=[N:11][CH:12]=1)(C)C.C([O-])([O-])=O.[K+].[K+]>C1COCC1.CO>[C:6]([C:7]1[CH:8]=[CH:9][C:10]([NH2:13])=[N:11][CH:12]=1)#[CH:5]

Participants

5

Reactant 2

HCID 11430Potassium CarbonateHCID 224828585-(2-(Trimethylsilyl)ethynyl)pyridin-2-amine

Product 1

HCID 219548275-Ethynylpyridin-2-amineYield 73.2%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 5-trimethylsilanylethynyl-pyridin-2-ylamine (example D.1 method 1 step 1) (32.08 g, 169 mmol) in THF (150 mL) and MeOH (350 mL) at 0° C. was added K2CO3 (2.33 g, 10 mol %) and the mixture was stirred at 0° C. for 5 h. Diluted with ice water (500 mL), extracted with TBME (3×500 mL), washed the combined organic layers with brine, dried over MgSO4. Removal of the solvent in vacuum left a dark brown solid, which was dissolved in hot ethyl acetate and precipitated with n-heptane trituration to give the 5-ethynyl-pyridin-2-ylamine (14.61 g, 73%) as a light brown solid. Evaporation of the mother liquor followed by silica gel column chromatography gave a brown solid which was triturated with ether and n-heptane to give a second crop of the title compound (3.26 g, 16%) as a light brown solid. MS (EI) 118.1 [(M)+]; mp 143° C.

Workup

  1. customat 0° C.
  2. extractionextracted with TBME (3×500 mL)
  3. washwashed the combined organic layers with brine
  4. dry with materialdried over MgSO4
  5. customRemoval of the solvent in vacuum
  6. waitleft a dark brown solid, which
  7. dissolutionwas dissolved in hot ethyl acetate
  8. customprecipitated with n-heptane trituration

Sources & evidence

ORD record
ord-3619fa69df394bd9868631a0e88b72ad
Source dataset
uspto-grants-2008_11
Patent number
US07446113B2

Reaction notes

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