Tin tetrachloride → Ethyl4-[2,2-dimethyl-4-(5-methyl-thien-2-yl)-benzo[1,2-g]-chrom-3-en-7-yl]benzoate

HRID 2621

Reaction equation

HRID 2621 reaction equation
C(OP([C:9](OC)(OC)[CH2:10][CH2:11][C:12]1[CH:22]=[CH:21][C:15]([C:16]([O:18][CH2:19][CH3:20])=[O:17])=[CH:14][CH:13]=1)(OCC)=O)C.[Li]CCCC.[CH3:32][C:33]1([CH3:51])[CH:42]=[C:41]([C:43]2[S:44][C:45]([CH3:48])=[CH:46][CH:47]=2)[C:40]2[C:35](=[CH:36][CH:37]=[C:38]([CH:49]=O)[CH:39]=2)[O:34]1.Cl[Sn](Cl)(Cl)Cl>C1COCC1.CCCCCC.C(OCC)(=O)C.ClCCl>[CH2:19]([O:18][C:16](=[O:17])[C:15]1[CH:14]=[CH:13][C:12]([C:11]2[CH:49]=[CH:38][C:37]3[CH:36]=[C:35]4[C:40]([C:41]([C:43]5[S:44][C:45]([CH3:48])=[CH:46][CH:47]=5)=[CH:42][C:33]([CH3:51])([CH3:32])[O:34]4)=[CH:39][C:9]=3[CH:10]=2)=[CH:22][CH:21]=1)[CH3:20]

Participants

9

Reactant 4

HCID 24287Tin tetrachlorideHCID 57037360Ethyl 4-(diethoxyphosphoryl-3,3-dimethoxypropyl)benzoate2×HCID 1317205762,2-Dimethyl-4(5-methyl-thien-2-yl)-chrom-3-en-6-al2×HCID 178418339Butyllithium

Product 1

HCID 15887284Ethyl4-[2,2-dimethyl-4-(5-methyl-thien-2-yl)-benzo[1,2-g]-chrom-3-en-7-yl]benzoate

Reagents, catalysts & solvents 4

HCID 6344DichloromethaneSolvent2×HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a cold (-78° C.) solution of ethyl 4-(diethoxyphosphoryl-3,3-dimethoxypropyl)benzoate (Compound D, 690 mg, 1.75 mmol) in THF (8 mL) was added n-BuLi in hexane (1.6M solution, 1.1 mL). The mixture was gradually warmed to ambient temperature over 30 min and stirred for 5 minutes. The mixture was recooled to -78° C. and 2,2-dimethyl-4(5-methyl-thien-2-yl)-chrom-3-en-6-al (Compound S, 300 mg, 1.1 mmol) in THF (1 mL) was added to the reaction mixture. The mixture was stirred at ambient temperature for 2 hours. The reaction mixture was diluted with ethyl acetate (100 mL) and washed with brine (10 mL) dried and the solvent was removed by evaporation. The material was subjected to flash chromatography on silica gel to obtain the E and Z olefinic compounds, which were dissolved in dichloromethane (5 mL) and cooled to -78° C. A solution of SnCl4 in dichloromethane (52 mg in 0.2 mL) was added to the olefinic compounds. The resulting mixture was stirred for 30 minutes, quenched with methanol, water and diluted with ethyl acetate (100 mL). The organic layer was washed with brine and dried. Solvent was removed under reduced pressure and purified by silicagel chromatography to afford the title compound as a white solid.

Workup

  1. customwas recooled to -78° C.
  2. stirringThe mixture was stirred at ambient temperature for 2 hours
  3. washwashed with brine (10 mL)
  4. customdried
  5. customthe solvent was removed by evaporation
  6. customto obtain the E and Z olefinic compounds, which
  7. temperaturecooled to -78° C
  8. stirringThe resulting mixture was stirred for 30 minutes
  9. customquenched with methanol, water
  10. additiondiluted with ethyl acetate (100 mL)
  11. washThe organic layer was washed with brine
  12. customdried
  13. customSolvent was removed under reduced pressure
  14. custompurified by silicagel chromatography

Sources & evidence

ORD record
ord-4fc614d343484a3da54bc68b788f4a1f
Source dataset
uspto-grants-1998_03
Patent number
US05728846

Linked notes

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