Carbon Dioxide → 7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine-3-carboxylic acid

HRID 2113789Notes

Reaction equation

HRID 2113789 reaction equation
Br[C:2]1[N:3]([CH3:20])[N:4]=[C:5]2[C:10]=1[CH2:9][CH2:8][CH2:7][N:6]2[C:11]1[C:16]([CH3:17])=[CH:15][C:14]([CH3:18])=[CH:13][C:12]=1[Cl:19].N1C2C(=CC=C3C=2N=CC=C3)C=CC=1.C([Li])CCC.[C:40](=[O:42])=[O:41]>O1CCCC1.C1CCCCC1>[Cl:19][C:12]1[CH:13]=[C:14]([CH3:18])[CH:15]=[C:16]([CH3:17])[C:11]=1[N:6]1[CH2:7][CH2:8][CH2:9][C:10]2=[C:2]([C:40]([OH:42])=[O:41])[N:3]([CH3:20])[N:4]=[C:5]12

Participants

7

Reactant 4

HCID 280Carbon Dioxide2×HCID 13181,10-PhenanthrolineHCID 113602163-bromo-7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridineHCID 178418339Butyllithium2×

Product 1

HCID 221362637-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine-3-carboxylic acid

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8078CyclohexaneSolvent

Conditions

Temperature
-78 °C

Procedure

3-Bromo-7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine (1-1; 1.46 g) and a few crystals of 1,10 phenanthroline were dissolved in 25 mL of dry tetrahydrofuran and chilled to −78° C. under an argon atmosphere. A 2.0 M solution of n-butyllithium in cyclohexane was added dropwise until the dark color of the phenanthroline/organolithium complex persisted. An additional 2.05 mL of the n-butyllithium solution was added. After 10 minutes, carbon dioxide, generated from dry ice, was bubbled through the reaction mixture for 5 minutes. After the reaction mixture had been stirred at −78° C. for 5 minutes, the cooling bath was removed and the mixture was allowed to warm for 5 minutes before being quenched by the addition of water. The mixture was partitioned between ethyl acetate and water, acidified with dilute hydrochloric acid. The ethyl acetate was dried with magnesium sulfate and concentrated. The residue was flash chromatographed on silica gel eluting with an acetone/hexane gradient to provide 1.11 g of 5-1: mp 247.8-248.3° C.

Workup

  1. customwas bubbled through the reaction mixture for 5 minutes
  2. customthe cooling bath was removed
  3. temperatureto warm for 5 minutes
  4. custombefore being quenched by the addition of water
  5. customThe mixture was partitioned between ethyl acetate and water
  6. dry with materialThe ethyl acetate was dried with magnesium sulfate
  7. concentrationconcentrated
  8. customchromatographed on silica gel eluting with an acetone/hexane gradient

Sources & evidence

ORD record
ord-a521d420823d4c06818acb4c0da0cda9
Source dataset
uspto-grants-2008_10
Patent number
US07432283B2

Reaction notes

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