Reaktion #579405

Reaktionsgleichung

benzo[b]thiophene

methacrylic acid

→

dark orange oil

Ausbeute 78.9%

2-methyl-1,2-dihydrobenzo[b]cyclopenta[d]thiophen-3-one

Ausbeute 78.9%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigestarting at 70° C. within 20 minutes to 1000 g of super-PPA
2. 2
   workup.DISTILLATIONMethylene chloride was distilled off
3. 3
   SonstigeAfter 2 h of reaction time
4. 4
   workup.ADDITIONthe reaction mixture was poured
5. 5
   Sonstigeonto crushed ice
6. 6
   workup.DISSOLUTIONhad completely dissolved
7. 7
   ExtraktionThe aqueous phase was extracted with a dichloromethane/hexane solvent mixture (30 parts by volume/70 parts by volume)
8. 8
   WaschenThe combined organic phases were washed with a saturated aqueous solution of sodium hydrogen-carbonate and with water
9. 9
   Trocknendried over magnesium sulfate
10. 10
    SonstigeAfter removing the solvents under reduced pressure

Vorschrift

A solution of 66.9 g of benzo[b]thiophene (0.5 mol) and 46.3 g of methacrylic acid (0.537 mol) in 60 ml of dichloromethane was added dropwise starting at 70° C. within 20 minutes to 1000 g of super-PPA. The temperature was maintained at 65-70° C. during the addition. Methylene chloride was distilled off. After 2 h of reaction time, the reaction mixture was poured onto crushed ice and stirred until the polyphosphoric acid had completely dissolved. The aqueous phase was extracted with a dichloromethane/hexane solvent mixture (30 parts by volume/70 parts by volume). The combined organic phases were washed with a saturated aqueous solution of sodium hydrogen-carbonate and with water and dried over magnesium sulfate. After removing the solvents under reduced pressure, 79.8 g of a dark orange oil (71%) were obtained.

Quelle