Diethyl Ether → 8-Bromo-2-chloro-10-methylene-10h-chromeno[3,2-b]pyridine

HRID 1970293Notes

Reaction equation

HRID 1970293 reaction equation
[Br:1][C:2]1[CH:15]=[CH:14][C:13]2[O:12][C:11]3[C:6](=[N:7][C:8]([Cl:16])=[CH:9][CH:10]=3)[C:5](=O)[C:4]=2[CH:3]=1.[CH3:18][Mg]Br.C(OCC)C.C(Cl)(Cl)Cl>C1COCC1>[Br:1][C:2]1[CH:15]=[CH:14][C:13]2[O:12][C:11]3[C:6](=[N:7][C:8]([Cl:16])=[CH:9][CH:10]=3)[C:5](=[CH2:18])[C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 6212ChloroformHCID 584661968-bromo-2-chloro-10H-chromeno[3,2-b]pyridin-10-oneHCID 178418573HCID 178418573, compound

Product 1

HCID 584661878-Bromo-2-chloro-10-methylene-10h-chromeno[3,2-b]pyridine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

To a suspension of 8-bromo-2-chloro-10H-chromeno[3,2-b]pyridin-10-one (20 g, 64.4 mmol) in 500 mL of THF at −78° C. was added dropwise methylmagnesium bromide 3.0 M in diethyl ether (13.82 mL, 116 mmol). The reaction was allowed to slowly warmed up to 0° C. in about 2 h. The reaction was quenched with NH4Cl solution, extracted with EtOAc, dried over Na2SO4, filtered and evaporated to give the corresponding crude tertiary alcohol. This solid residue was re-dissolved in 100 mL of THF and treated with mL of chloroform and the resulting solution was evaporated on a 75° C. water bath for 10 min to give crude 8-bromo-2-chloro-10-methylene-10H-chromeno[3,2-b]pyridine as a brownish solid.

Workup

  1. customThe reaction was quenched with NH4Cl solution
  2. extractionextracted with EtOAc
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. customevaporated
  6. customto give the corresponding crude tertiary alcohol
  7. customthe resulting solution was evaporated on a 75° C. water bath for 10 min

Sources & evidence

ORD record
ord-3cc63789030449418d413814e7c59c20
Source dataset
uspto-grants-2013_04
Patent number
US08426447B2

Reaction notes

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