Water → (Z)-2-bromo-6-(1-(4-chlorophenyl)-3-dimethylaminoallyl)pyridine

HRID 1731302Notes

Reaction equation

HRID 1731302 reaction equation
C([Li])CCC.[Br-].[CH3:7][N:8]([CH3:30])[CH2:9][CH2:10][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Br:31][C:32]1[CH:37]=[CH:36][CH:35]=[C:34]([C:38](=O)[C:39]2[CH:44]=[CH:43][C:42]([Cl:45])=[CH:41][CH:40]=2)[N:33]=1.O>O1CCCC1>[Br:31][C:32]1[CH:37]=[CH:36][CH:35]=[C:34]([CH:38]([C:39]2[CH:44]=[CH:43][C:42]([Cl:45])=[CH:41][CH:40]=2)/[CH:10]=[CH:9]\[N:8]([CH3:30])[CH3:7])[N:33]=1

Participants

6

Reactant 4

HCID 962WaterHCID 2724136(2-(Dimethylamino)ethyl)triphenylphosphonium bromideHCID 13191799(6-Bromopyridin-2-yl)(4-chlorophenyl)methanoneHCID 178418339Butyllithium

Product 1

HCID 86741093(Z)-2-bromo-6-(1-(4-chlorophenyl)-3-dimethylaminoallyl)pyridine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of n-butyllithium (60 mL, 1.55M in hexane) was added dropwise during 45 min to a stirred suspension of (2-dimethylaminoethyl)triphenylphosphonium bromide (38.1 g) in dry tetrahydrofuran (500 mL) under nitrogen. After an additional hour at room temperature, a solution of 2-bromo-6-(4-chlorobenzoyl)pyridine (27.3 g) in dry tetrahydrofuran (200 mL) was added dropwise. The mixture was stirred at room temperature for 20 min, then refluxed for 80 min, cooled to room temperature, and poured into water (500 mL). The ether layer was separated and the aqueous phase extracted with three additional portions of ether. The ether layers were combined, washed once with water, dried (MgSO4) and evaporated to give an oil which was triturated with hexane (500 mL). The hexane layer was decanted and concentrated to give a crude mixture of isomeric Z and E alkenes which were separated by chromatography (Waters Prep 500) on silica gel with 95:5/methylene chloride: methanol (E, 7.53 g; Z, 15.19 g). The individual isomers were then rechromatographed on silica gel with ethyl acetate to yield (Z)-2-bromo-6-(1-(4-chlorophenyl)-3-dimethylaminoallyl)pyridine, m.p. 56°-62°, and (E)-2-bromo-6-(1-(4-chlorophenyl-3-diomethylaminoallyl)pyridine, 69°-70°.

Workup

  1. waitAfter an additional hour at room temperature
  2. temperaturerefluxed for 80 min
  3. temperaturecooled to room temperature
  4. customThe ether layer was separated
  5. extractionthe aqueous phase extracted with three additional portions of ether
  6. washwashed once with water
  7. dry with materialdried (MgSO4)
  8. customevaporated
  9. customto give an oil which
  10. customwas triturated with hexane (500 mL)
  11. customThe hexane layer was decanted
  12. concentrationconcentrated
  13. customto give a crude
  14. customwere separated by chromatography (Waters Prep 500) on silica gel with 95:5/methylene chloride
  15. customThe individual isomers were then rechromatographed on silica gel with ethyl acetate

Sources & evidence

ORD record
ord-e525c5f0aead41f78d442510c578fb22
Source dataset
uspto-grants-1986_11
Patent number
US04621094

Reaction notes

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