[Na].N.[Cl:3][C:4]1[CH:5]=[CH:6][C:7]([OH:20])=[C:8]([C:10]([CH2:18][CH3:19])([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[OH:11])[CH:9]=1.Cl[CH:22](Cl)[C:23]([O-:25])=[O:24].[K+]>C1(C)C=CC=CC=1.O>[Cl:3][C:4]1[CH:5]=[CH:6][C:7]2[O:20][CH:22]([C:23]([OH:25])=[O:24])[O:11][C:10]([CH2:18][CH3:19])([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[C:8]=2[CH:9]=1
4.8 g of sodium were added in small amounts to a stirred mixture of 250 ml of condensed liquid ammonia and 100 mg of ferric nitrate and then a solution of 26.2 g of 5-chloro-α-ethyl-2-hydroxy-α-phenyl-benzene-methanol [prepared by Step A of Example 23 using ethyl bromide] with a melting point of 85° C. in 200 ml of anhydrous toluene was added thereto at 28°-30° C. over 90 minutes. The temperature was raised to disengage the ammonia and the mixture was then refluxed for 3 hours. 100 ml of toluene was added thereto followed by addition of 18 g of potassium dichloroacetate at 50° C. The mixture was refluxed overnight and 9 g of potassium dichloroacetate were added thereto. The mixture was refluxed for 2 more hours and was cooled and poured into water. The organic phase was decanted and the aqueous phase was acidified and extracted with ether. The ether extracts were washed 3 times with 500 ml of water and was extracted 3 times with 300 ml of sodium bicarbonate solution. The combined aqueous phases were washed twice with 500 ml of ether, were acidified with concentrated hydrochloric acid and extracted 3 times with 500 ml of ether. The ether extracts were washed with water, dried over magnesium sulfate and evaporated to dryness under reduced pressure to obtain 27 g of raw 6-chloro-4-ethyl-4-phenyl-[4H]-1,3-benzodioxin-2-carboxylic acid. (mixture of two racemates diastereoisomers).
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