Phosphorus oxychloride → 2H-Indazole, 3-chloro-2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-

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Reaction Steps

10.0 Parts of 2-(4-chloro-2-fluorophenyl)-1,2,4,5,6,7 -hexahydro-3H-indazol-3-one and 7.3 parts of phosphorous oxychloride were mixed and heated to 130°-150° for six hours. The reaction mixture was dissolved in 100 parts of chloroform. The organic solution containing the product was washed successively with three portions of 25 parts each of 10% sodium hydroxide and then washed with 50 parts water. The chloroform solution was dried with 2-10 parts of anhydrous sodium sulfate and then filtered. The solvent was removed under a reduced pressure on a rotary evaporator. The resulting thick oil was purified by sublimation at 100°-120° at 0.5-1.5 mm. pressure to yield 7.8 parts of white crystalline material with m.p. 88°-89.5°.

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