Reaction equation
[Br:1][C:2]1[S:3][C:4]([Br:7])=[CH:5][CH:6]=1.[CH:8]([N-]C(C)C)([CH3:10])[CH3:9].[Li+].CN([CH:19]=[O:20])C.[OH2:21]>C1COCC1>[CH3:19][O:20][C:9](=[O:21])/[CH:8]=[CH:10]/[C:6]1[CH:5]=[C:4]([Br:7])[S:3][C:2]=1[Br:1]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
To 2,5-Dibromothiophene (1.5 g, 6.2 mmol in THF (30 mL) cooled to −78° C. was added lithium diisopropylamide (6.2 mL, 6.2 mmol; 1.0M in THF, 6.2 mmol;) dropwise. The mixture was stirred 5 min, and was quenched with DMF (1.4 g, 18.6 mmol). Stirring was continued for 15 min at −78° C. and water was added. The THF was evaporated, Et2O was added and the organic phase was separated and washed with water, 1% HCl, water (3×) and brine. The organic phase was passed through a silica plug and toluene (20 mL) was added. Methyl(triphenylphosphonanylidene) acetate (3.34 g, 10.0 mmol) was added at 23° C. and the mixture was stirred for 12 h. The solvents were then evaporated, ether was added and the mixture was passed through a silica plug. The mixture was concentrated in vacuo and dried overnight via high vacuum and 585 mg of the above named enoate was obtained as a tan solid.
Workup
- stirringStirring
- waitwas continued for 15 min at −78° C.
- customThe THF was evaporated
- additionEt2O was added
- customthe organic phase was separated
- washwashed with water, 1% HCl, water (3×) and brine
- additionwas added
- stirringthe mixture was stirred for 12 h
- customThe solvents were then evaporated
- additionether was added
- concentrationThe mixture was concentrated in vacuo
- customdried overnight via high vacuum and 585 mg of the
- customwas obtained as a tan solid
Sources & evidence
- ORD record
- ord-b2e5337e512d4d0591f23cacaa251d7a
- Source dataset
- uspto-grants-2002_03
- Patent number
- US06359181B1
Linked notes
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