Methacrylic Acid → 4,5-Dihydro-2,5-dimethyl-6H-cyclopenta[b]thiophen-6-one
Reaction equation
[CH3:1][C:2]1[S:3][CH:4]=[CH:5][CH:6]=1.[C:7]([OH:12])(=O)[C:8]([CH3:10])=[CH2:9]>ClCCl>[CH3:1][C:2]1[S:3][C:4]2[C:7](=[O:12])[CH:8]([CH3:10])[CH2:9][C:5]=2[CH:6]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 80 °C
Procedure
A solution of 100 g of 2-methylthiophene (1.02 mol) and 104 ml of methacrylic acid (1.22 mol) in 200 ml of dichloromethane was added dropwise within 30 minutes at 80° C. to 1000 g of super-PPA. Afterwards, the reaction mixture was stirred at 80° C. for 3 hours. The dark red mixture was poured into 1000 g of crushed ice and stirred until the polyphosphoric acid had completely dissolved. The aqueous phase was extracted twice with 400 ml each time of 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 hydrogencarbonate and dried over magnesium sulfate. After removal of the solvents on a rotary evaporator, 136 g of crude product were obtained. The distillation of the crude product (90° C., 0.1 torr) gave 76 g (46%) of product.
Workup
- dissolutionhad completely dissolved
- extractionThe aqueous phase was extracted twice with 400 ml each time of a dichloromethane/hexane solvent mixture (30 parts by volume/70 parts by volume)
- washThe combined organic phases were washed with a saturated aqueous solution of sodium hydrogencarbonate
- dry with materialdried over magnesium sulfate
- customAfter removal of the solvents
- customon a rotary evaporator
- custom136 g of crude product were obtained
- distillationThe distillation of the crude product (90° C., 0.1 torr)
Sources & evidence
- ORD record
- ord-118b34a9daaa41619b22bf9fbdc8d16b
- Source dataset
- uspto-grants-2009_05
- Patent number
- US07531672B2
Reaction notes
Loading…