Methanol--water (1/1) → Ethyl 3-methyl-7-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)-2,4,6-octatrienoate

HRID 2106740Notes

Reaction equation

HRID 2106740 reaction equation
[Br-].[CH3:2][C:3]1([CH3:35])[C:11]2[CH:10]=[C:9]([CH:12]([P+](C3C=CC=CC=3)(C3C=CC=CC=3)C3C=CC=CC=3)[CH3:13])[S:8][C:7]=2[C:6]([CH3:34])([CH3:33])[CH2:5][CH2:4]1.[CH:36]([CH:38]=[CH:39][C:40]([CH3:47])=[CH:41][C:42]([O:44][CH2:45][CH3:46])=[O:43])=O.CO.O>C1OCCC1>[CH3:47][C:40]([CH:39]=[CH:38][CH:36]=[C:12]([C:9]1[S:8][C:7]2[C:6]([CH3:33])([CH3:34])[CH2:5][CH2:4][C:3]([CH3:2])([CH3:35])[C:11]=2[CH:10]=1)[CH3:13])=[CH:41][C:42]([O:44][CH2:45][CH3:46])=[O:43]

Participants

5

Reactant 3

HCID 22242641Methanol--water (1/1)HCID 23049224[1-(4,5,6,7-Tetrahydro-4,4,7,7-tetramethylbenzo-[b]thien-2-yl)ethyl]triphenylphosphonium bromideHCID 54439227Ethyl 5-formyl-3-methyl-2,4-pentadienoate

Product 1

HCID 53882835Ethyl 3-methyl-7-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)-2,4,6-octatrienoateYield 83.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

4.50 g of [1-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)ethyl]triphenylphosphonium bromide and 1.3 g of ethyl 5-formyl-3-methylpenta-2,4-dienoate are dissolved in 70 ml of butylene oxide and the solution is heated at reflux for 2 hours. The cooled mixture is poured into a methanol/water mixture (6:4) and extracted several times with hexane. The hexane phase is washed three times with water, dried and evaporated. After filtration of the crude product over silica gel (eluting agent hexane/ether 9:1), there are obtained 2.4 g of ethyl 3-methyl-7-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)-2,4,6-octatrienoate as a pale yellowish oil.

Workup

  1. temperaturethe solution is heated
  2. temperatureat reflux for 2 hours
  3. extractionextracted several times with hexane
  4. washThe hexane phase is washed three times with water
  5. customdried
  6. customevaporated
  7. filtrationAfter filtration of the crude product over silica gel (eluting agent hexane/ether 9:1), there

Sources & evidence

ORD record
ord-264c413c47ad496c9ed9e626169289cd
Source dataset
uspto-grants-1990_06
Patent number
US04931458

Reaction notes

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