[Cl:1][CH:2]1[CH:7]([CH2:8][C:9]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=O)[CH2:6][CH2:5][CH2:4][CH2:3]1.P(Cl)(Cl)(Cl)(Cl)Cl.[NH2-].[Na+].N>C1COCC1.CCOCC.O>[Cl:1][C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][C:7]=1[C:8]#[C:9][CH:11]1[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12]1
3-Chloro-4-cyclohexylacetophenone (0.25 moles) and phosphorus pentachloride (0.31 moles) are placed in a 3-necked flask equipped with a mechanical stirrer, a condenser connected to a nitrogen inlet, and a thermometer. The mixture is stirred at 33°-35° C for 3 days. The cooled reaction mixture is poured onto 800 g. of ice and extracted with 3 × 500 ml. of ether. The ether fraction is washed with 2 × 100 ml water 4 × 100 ml of 5% sodium hydroxide, 3 × 50 ml water, 2 × 50 ml of saturated saline and dried over sodium sulfate. The ether is removed to give the chlorinated intermediate. The intermediate is dissolved in anhydrous THF (200 ml) and is added dropwise to a freshly prepared solution of sodamide in liquid ammonia, using a dry-ice condenser. The reaction mixture is allowed to stir at room temperature overnight; then, it is poured into 50 ml of water and 500 ml of ether. The ether fraction is washed with 3 × 50 ml water and 50 ml of saturated saline and is dried over sodium sulfate. Removal of solvent gives a residue which is distilled to give 3-chloro-4-cyclohexylethynylbenzene.
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