Formaldehyde → 2-(2,4-Dichlorophenyl)-2-(phenylsulfonyl)ethyl acetate

HRID 1297501Notes

Reaction equation

HRID 1297501 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[CH2:9][S:10]([C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)(=[O:12])=[O:11].C(NC(C)C)(C)C.[Li]CCCC.C=O.N1C=CC=CC=1.[CH3:39][C:40]([O:42][C:43](C)=O)=[O:41]>C1COCC1>[C:40]([O:42][CH2:43][CH:9]([C:3]1[CH:4]=[CH:5][C:6]([Cl:8])=[CH:7][C:2]=1[Cl:1])[S:10]([C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][CH:18]=1)(=[O:12])=[O:11])(=[O:41])[CH3:39]

Participants

8

Reactant 6

HCID 712FormaldehydeHCID 1049PyridineHCID 7912DiisopropylamineHCID 7918Acetic AnhydrideHCID 20191362HCID 20191362, compoundHCID 178418339Butyllithium

Product 1

HCID 589147942-(2,4-Dichlorophenyl)-2-(phenylsulfonyl)ethyl acetateYield 94%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

The crude sulfone (2) (1 eq) in THF was added dropwise via addition funnel to a freshly prepared solution of diisopropylamine (1.3 eq), n-BuLi 2.5 M in hexanes (1.1 eq) and THF under N2 at −78° C. with stirring. After 30 min., the paraformaldehyde was added (2.1 eq). The reaction was stirred for an additional 30 min. at which time the reaction was allowed to warm to room temperature over 4.5 h. The reaction was then quenched with sat. aq. NH4Cl. The aqueous layer was extracted with EtOAc, dried (Na2SO4), filtered and concentrated under reduced pressure to yield the crude sulfonyl hydrin which was used without further purification. The crude sulfonyl hydrin was dissolved in CH2Cl2 (excess) and pyridine (1.2 eq) followed by the addition of Ac2O (1.1 eq). After stirring at room temperature for 14.5 h, the reaction was quenched with sat. aq. NH4Cl. The layers were separated, and the aqueous layer was extracted with Et2O. The combined organic layers were dried (Na2SO4), filtered, and concentrated to give the 2-(2,4-dichlorophenyl)-2-(phenylsulfonyl)ethyl acetate (3) (94% yield) in high purity.

Workup

  1. stirringThe reaction was stirred for an additional 30 min. at which time the reaction
  2. customThe reaction was then quenched with sat. aq. NH4Cl
  3. extractionThe aqueous layer was extracted with EtOAc
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customto yield the crude sulfonyl hydrin which
  8. customwas used without further purification
  9. dissolutionThe crude sulfonyl hydrin was dissolved in CH2Cl2 (excess)
  10. stirringAfter stirring at room temperature for 14.5 h
  11. customthe reaction was quenched with sat. aq. NH4Cl
  12. customThe layers were separated
  13. extractionthe aqueous layer was extracted with Et2O
  14. dry with materialThe combined organic layers were dried (Na2SO4)
  15. filtrationfiltered
  16. concentrationconcentrated

Sources & evidence

ORD record
ord-a785ef493a2347419ab20de592add0b3
Source dataset
uspto-grants-2007_07
Patent number
US07250443B2

Reaction notes

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