Hydrazinecarboxylic acid, ethyl ester → ethyl 2[5-fluoro-2-(4-fluorophenyl)-2,3-dihydro-1H-inden-1-ylidene]hydrazine carboxylate

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Reaction Steps

To a mixture of 1.5 g of 5-fluoro-2-(4-fluorophenyl)-2,3-dihydro-1H-inden-1-one (prepared by a procedure analogous to Example 1, Step B) and 0.63 g of ethyl carbazate in 20 ml of methanol was added 1 drop of conc. H2SO4 and the reaction was refluxed under nitrogen overnight. The reaction was then partitioned between ethyl acetate and 5% aqueous NaHCO3, the aqueous extracts were washed with ethyl acetate and the combined organic extracts were dried over MgSO4. Concentration of the organic extract afforded 1.9 g of a yellow oil, which was triturated with ether to afford 1.27 g of a white solid, m.p. 139°-141° C. 1H NMR (CDCl3) δ 1.26 (t, 3H), 2.91 (dd, 1H), 3.70 (dd, 1H), 4.2 (m, 3H), 6.9-7.3 (m, 6H), 7.52 (bs, 1H ), 7.93 (dd, 1H ).

Provenance & Evidence