Hydrochloric Acid → HCID 21107217, compound

HRID 2377344Notes

Reaction equation

HRID 2377344 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7](=O)[CH2:6][C:5]2([CH3:14])[CH3:13].[CH2:15]([Mg]Br)[CH3:16].Cl.[C:20]1(C)C=CC(S(O)(=O)=O)=C[CH:21]=1>O1CCCC1.C1C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH2:15][CH3:16])([CH2:20][CH3:21])[CH2:6][C:5]2([CH3:14])[CH3:13]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6101p-Toluenesulfonic acidHCID 225689232H-1-Benzopyran-2-one, 6-bromo-3,4-dihydro-4,4-dimethyl-HCID 178418443HCID 178418443, compound

Product 1

HCID 21107217HCID 21107217, compoundYield 84%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 6-bromo-4,4-dimethyl-chroman-2-one (U.S. Pat. No. 6,252,090, 4 g, 15.7 mmol) in anhydrous tetrahydrofuran (20 mL) was treated with a 3M solution of ethyl magnesium bromide (10.5 mL, 31.5 mmol) and stirred at ambient temperature for 2 h. The reaction mixture was poured into cold dilute hydrochloric acid and extracted with ethyl acetate (×2). The combined organic extract was dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to afford a residue which was dissolved in 50 mL of benzene, treated with p-toluene sulfonic acid (1 g, 3.92 mmol) and the resulting reaction mixture was refluxed overnight. The reaction mixture cooled to ambient temperature, filtered on silica gel and washed with 10% ethyl acetate in hexane. The filtrate and washings were evaporated in vacuo to an oil which was subjected to flash column chromatography over silica gel (230-400 mesh) using 5% ethyl acetate in hexane as the eluent to afford the title compound as a pale yellow oil (3.9 g, 84%).

Workup

  1. extractionextracted with ethyl acetate (×2)
  2. extractionThe combined organic extract
  3. dry with materialwas dried over anhydrous sodium sulfate
  4. filtrationfiltered
  5. customevaporated in vacuo
  6. customto afford a residue which
  7. customthe resulting reaction mixture
  8. temperaturewas refluxed overnight
  9. temperatureThe reaction mixture cooled to ambient temperature
  10. filtrationfiltered on silica gel
  11. washwashed with 10% ethyl acetate in hexane
  12. customThe filtrate and washings were evaporated in vacuo to an oil which

Sources & evidence

ORD record
ord-8cd9a7a05a044f36934022ab61d846e3
Source dataset
uspto-grants-2008_12
Patent number
US07468391B2

Reaction notes

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