Methanol → 7-bromo-3-chloro-5-(2-methoxyethylidene)-5H-chromeno[2,3-c]pyridine

HRID 335981Notes

Reaction equation

HRID 335981 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:14](=[CH:15][CH:16]=1)[O:13][C:7]1[CH:8]=[N:9][C:10]([Cl:12])=[CH:11][C:6]=1[C:5]2([CH:18]=[CH2:19])O.[CH3:20][OH:21].S(=O)(=O)(O)O>>[Br:1][C:2]1[CH:3]=[C:4]2[C:14](=[CH:15][CH:16]=1)[O:13][C:7]1[CH:8]=[N:9][C:10]([Cl:12])=[CH:11][C:6]=1[C:5]2=[CH:18][CH2:19][O:21][CH3:20]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 866585017-bromo-3-chloro-5-vinyl-5H-chromeno[2,3-c]pyridin-5-ol

Product 1

HCID 866585007-bromo-3-chloro-5-(2-methoxyethylidene)-5H-chromeno[2,3-c]pyridineYield 92.3%

Conditions

Temperature
50 °C

Procedure

To a sealed vessel was added 7-bromo-3-chloro-5-vinyl-5H-chromeno[2,3-c]pyridin-5-ol (2.50 g, 7.38 mmol), methanol (59.8 mL, 1477 mmol) and sulfuric acid (0.2M in water) (3.70 mL, 0.74 mmol). The clear solution was heated to 50° C. over the weekend. The reaction mixture became light yellow heterogenous. The solvent was removed by rotovap and the residue was diluted with 125 mL of EtOAc. The organic solution was washed with saturated aqueous NaHCO3 and brine, dried over MgSO4, filtered and concentrated in vacuo to give the crude material 7-bromo-3-chloro-5-(2-methoxyethylidene)-5H-chromeno[2,3-c]pyridine (2.40 g, 6.81 mmol, 92% yield) as a yellow solid.

Workup

  1. customThe solvent was removed by rotovap
  2. additionthe residue was diluted with 125 mL of EtOAc
  3. washThe organic solution was washed with saturated aqueous NaHCO3 and brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-23f4fa9b66d94e928510889010060170
Source dataset
uspto-grants-2014_11
Patent number
US08883782B2

Reaction notes

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