2,4,5-Trichlorophenol → HCID 15159979, compound

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Reaction Steps

2.6 g (0.008 mole) of N-benzyloxycarbonyl-N-ethyl-D-phenylalanine (Example 3, Step 2) are dissolved in 10 ml of tetrahydrofuran and at 0° C. 1.6 g (0.008 mole) of 2,4,5-trichlorophenol and 1.65 g (0.008 mole) of dicyclohexylcarbodiimide are added, then the mixture is left to stand at room temperature for 4 hours. The residue is dissolved in 40 ml of benzene, washed twice with 20 ml of a 5 percent solution of sodium hydrogen carbonate, twice with 20 ml of water, then it is dried over anhydrous sodium sulfate and evaporated on a water bath having a temperature of about 40° C. at 15 to 20 millibars. The residual oil is dissolved in 10 ml of pyridine, 0.92 g (0.008 mole) of L-proline and 1.12 ml (0.008 mole) of triethylamine are added and the mixture is stirred till the dissolution of proline at room temperature. Then the solution is left to stand for 4 to 5 hours, subsequently it is evaporated on a water bath having a temperature of about 40° C. at 15 to 20 millibars. The residue is dissolved in a mixture of 25 ml of water and 10 ml of diethyl ether. The aqueous layer is washed twice with 10 ml of diethyl ether and the combined ether extracts are washed with 10 ml of a 5 percent solution of sodium hydrogen carbonate. The aqueous layers are combined and acidified to pH 2 with 3N hydrochloric acid. The separated product is extracted three times with 15 ml of benzene, the benzene layers are combined, washed three times with 5 ml of water, dried over anhydrous sodium sulfate and evaporated on a water bath having a temperature of about 40° C. at 15 to 20 millibars. Yield 2.2 g (64%) of an oil.

Provenance & Evidence