Tin tetrachloride → HCID 10149127, compound

HRID 1059745Notes

Reaction equation

HRID 1059745 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([S:9][C:10]([CH3:16])([CH3:15])[CH2:11][C:12]([OH:14])=O)=[CH:5][CH:4]=1.C(Cl)(=O)C(Cl)=O.Cl[Sn](Cl)(Cl)Cl>C1C=CC=CC=1.C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:6](=[CH:7][CH:8]=1)[S:9][C:10]([CH3:16])([CH3:15])[CH2:11][C:12]2=[O:14]

Participants

6

Reactant 3

HCID 24287Tin tetrachlorideHCID 65578Oxalyl chlorideHCID 10171427Butanoic acid, 3-[(4-methoxyphenyl)thio]-3-methyl-

Product 1

HCID 10149127HCID 10149127, compoundYield 78.3%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolvent2×HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 3-(4-methoxy-phenylsulfanyl)-3-methyl-butyric acid (20.0 g, 83.2 mmol) in 250 mL of benzene at room temperature was added a solution of oxalyl chloride (15.84 g, 124.8 mmol) in 10 mL of benzene over 30 minutes. After 4 hours the solution was washed with ice cold 5% aqueous NaOH (CAUTION: a large volume of gas is released during this procedure), followed by ice cold H2O, and finally saturated aqueous NaCl. The solution was dried (Na2SO4) and concentrated under reduced pressure to give a clear yellow oil. This material was used without further purification in the next step. 1H NMR (300 MHz, CDCl3) δ: 7.45 (2H, d, J=8.8 Hz), 6.90 (2H, d, J=8.8 Hz), 3.84 (3H, s), 3.12 (2H, s), 1.41 (6H, s). Step 3: To a solution of the acyl chloride product of Step 2 (21.5 g, 83.2 mmol) in 250 mL of CH2Cl2 at 0° C. was added dropwise a solution of SnCl4 (21.7 g, 83.2 mmol) in 30 mL of CH2Cl2. After 2 hours the reaction was quenched by slow addition of 150 mL H2O. The organic layer was washed with 1M aqueous HCl, 5% aqueous NaOH, H2O, and finally saturated aqueous NaCl before being dried over MgSO4. Concentration under reduced pressure and vacuum distillation of the residual oil (Bulb-to-bulb, 125-135° C., 5 mm/Hg) afforded 14.48 g (78%) of 6-methoxy-2,2-dimethyl-thiochroman4-one as a pale-yellow oil. 1H NMR (300 MHz, CDCl3) δ: 7.62 (1H, d, J=2.9 Hz), 7.14 (1H, d, J=8.6 Hz), 7.03 (1H, dd, J=2.8 Hz), 3.83 (3H, s), 2.87 (2H, s), 1.46 (6H, s).

Workup

  1. washAfter 4 hours the solution was washed with ice cold 5% aqueous NaOH (CAUTION
  2. dry with materialThe solution was dried (Na2SO4)
  3. concentrationconcentrated under reduced pressure
  4. customto give a clear yellow oil
  5. customThis material was used without further purification in the next step
  6. customAfter 2 hours the reaction was quenched by slow addition of 150 mL H2O
  7. washThe organic layer was washed with 1M aqueous HCl, 5% aqueous NaOH, H2O, and finally saturated aqueous NaCl
  8. dry with materialbefore being dried over MgSO4
  9. concentrationConcentration
  10. distillationunder reduced pressure and vacuum distillation of the residual oil (Bulb-to-bulb, 125-135° C., 5 mm/Hg)

Sources & evidence

ORD record
ord-5221c56610174e47a982b3141e40165f
Source dataset
uspto-grants-2003_02
Patent number
US06521641B1

Reaction notes

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