Hydrochloric Acid → 2-Chloro-5-(3,4-dimethoxybenzoyl)pyridine

HRID 1031498Notes

Reaction equation

HRID 1031498 reaction equation
[Mg].Br[C:3]1[CH:4]=[C:5]([O:11][CH3:12])[C:6]([O:9][CH3:10])=[CH:7][CH:8]=1.COC1C=C([Mg]Br)C=CC=1OC.[Cl:25][C:26]1[CH:34]=[CH:33][C:29]([C:30](Cl)=[O:31])=[CH:28][N:27]=1.Cl>O1CCCC1>[Cl:25][C:26]1[CH:34]=[CH:33][C:29]([C:30](=[O:31])[C:3]2[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[C:5]([O:11][CH3:12])[CH:4]=2)=[CH:28][N:27]=1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 76114Benzene, 4-bromo-1,2-dimethoxy-HCID 27821656-Chloronicotinoyl ChlorideHCID 5462224MagnesiumHCID 178491916HCID 178491916, compound

Product 1

HCID 148232212-Chloro-5-(3,4-dimethoxybenzoyl)pyridineYield 67.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To 200 ml of tetrahydrofuran were added metallic magnesium (5.35 g) and 4-bromoveratrole (47.8 g), and the mixture was heated for 3 hours under reflux to prepare a 3,4-dimethoxyphenyl magnesium bromide solution. This solution was added, while stirring, dropwise at temperatures ranging from -50° C. to -60° C. to a solution of 6-chloronicotinic acid chloride (21.2 g) in tetrahydrofuran (200 ml) (the time required for the addition: one hour). The resultant mixture was stirred at the same temperature for 2 hours and 40 minutes, and there was then added 2N hydrochloric acid (100 ml). Precipitating crystals were collected by filtration, washed with water and dried to afford 2-chloro-5-(3,4-dimethoxybenzoyl)pyridine (22.5 g), m.p. 158° to 159° C.

Workup

  1. temperaturethe mixture was heated for 3 hours
  2. temperatureunder reflux
  3. additionThis solution was added
  4. additionrequired for the addition
  5. customone hour
  6. customPrecipitating crystals
  7. filtrationwere collected by filtration
  8. washwashed with water
  9. customdried

Sources & evidence

ORD record
ord-08caf5d4817b4389807aea87041433cf
Source dataset
uspto-grants-1990_09
Patent number
US04954497

Reaction notes

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