[O:1]1[CH2:5][CH2:4][O:3][CH:2]1[C:6]1[CH:10]=[CH:9][S:8][C:7]=1[CH2:11][C:12]#[N:13].Br[CH:15]([CH3:17])[CH3:16].[OH-].[K+]>CS(C)=O.[I-].C([N+](CCCC)(CCCC)CCCC)CCC.[Cl-].[Na+].O>[O:1]1[CH2:5][CH2:4][O:3][CH:2]1[C:6]1[CH:10]=[CH:9][S:8][C:7]=1[CH:11]([CH2:16][CH2:15][CH3:17])[C:12]#[N:13]
1.43 g (7.32 mmol) of 3-(1,3-dioxolan-2-yl)-2-thiopheneacetonitrile was dissolved in 2 ml of dimethyl sulfoxide, and 1.08 g (8.78 mmol) of 2-bromopropane, 100 mg (cat) of tetra-n-butylammonium iodide and 3 ml of 50% potassium hydroxide were successively added. After 25 minutes, 300 mg of 2-bromopropane, further after 50 minutes, 1 ml of 50% potassium hydroxide and 2 ml of DMSO were added. After completion of the reaction, brine was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and evaporated, to obtain a crude product. The crude product was subjected to 100 g of silica gel (ethyl acetate:hexane=1:8), to give 853 mg (3.59 mmol, 49.1%) of the title compound as a yellow oil.
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