Water → 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].CS(O)(=O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.O>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
Procedure
A mixture of 150 g of 2-methylthiophene (1.5 mol) and 157.5 g of methacrylic acid (1.8 mol) was added within 30 minutes at about 80° C. to 1500 ml of Eaton's reagent, and the temperature was between 78° C. and 83° C. On completion of addition, the reaction mixture was stirred for a further 5 minutes and then gradually poured into a vigorously stirred mixture of 3000 ml of water and 500 ml of dichloromethane. The organic phase was removed and dried over magnesium sulfate. The solvent was distilled off on a rotary evaporator and 263.5 g of crude product were obtained in a purity of 88.2% according to GC-MS analysis. A portion of the crude product (79 g) was distilled (92° C., 0.02 torr). 56.5 g (76%) of product were obtained as a mixture of two isomers in a ratio of approx. 9:1 (thiophen-6-one: thiophen-4-one).
Workup
- customwas between 78° C. and 83° C
- additionOn completion of addition
- customThe organic phase was removed
- dry with materialdried over magnesium sulfate
- distillationThe solvent was distilled off on a rotary evaporator
- custom263.5 g of crude product were obtained in a purity of 88.2%
- distillationA portion of the crude product (79 g) was distilled (92° C., 0.02 torr)
Sources & evidence
- ORD record
- ord-92cbba399882467e8c8a975035eaa129
- Source dataset
- uspto-grants-2009_05
- Patent number
- US07531672B2
Reaction notes
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