The Synthesis of Quinolines from Aryloxyketones by the Method of

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ARTHURM. DOWELL, JR., HOWARD S. MCCULLOUGH,AND PAUL K. CALAWAY [CONTRIBUTION FROM THE DEPARTMENT OF CHEMISTRY, THEGEORGIA &XIOOL

OF

Vol. 70

TECHNOLOGY]

The Synthesis of Quinolines from Aryloxyketones by the Method of Pfitzinger BY ARTHUR M. DOWELL, JR.,' HOWARD S. MCCULLOUGH AND PAUL K. CALAWAY In a recent investigation2in this Laboratory we have utilized the tolylthiopropanones in the preparation of substituted quinoline acids by the method of Pfitzinger.* . The availability of the cresols suggested the preparation of the toloxypropanones4 and their ultimate condensation with isatin and 5-methylisatin, respectively, to produce six substituted cinchoninic acids. We have studied also the condensation of 5-methylisatin with both a-and fl-naphthoxyacetone.6 In previous papers6.' it has been demonstrated that the product of condensatiop of isatin with aryloxy ketones has been the 3-aryloxy-4Lquinaldinecarboxylic acid rather than the isomeric 2aryloxymethylcinchoninic acid. The aryloxy ketones used in this investigation were prepared from the corresponding phenols and chloraacetone by the method of Hurd and Perletz.8 The yields ranged from 5iy0 of the theoretical, in the case of the m-toloxyacetone, to 9i% for the 0-naphthoxyacetone. The potassium salts of the quinaldinecarboxylic acids prepared showed a tendency to foam in water solution and were salted out by high concentrations of potassium hydroxide. All of the acids exhibited a tendency to hold water of crystallization.* This water was removed by drying for several days in a vacuum desiccator over phosphorus pentoxide. Decarboxylation of the compounds was observed to start around 175'; hence melting point values varied with the rate of heating.

Experimental Preparation of Ary1oxyacetones.-The procedure used for the condensation of chloroacetone with phenols was based on the method of Hurd and Perletz.8 T o a vigorously stirred and refluxing suspension of 0.41 mole of the phenol and 57 g. (0.41 mole) of anhydrous potassium carbonate in 150 ml. of dry acetone was added over a period of one hour a solution of 50 g. (0.54 mole) of chloroacetone and 3 g. of powdered potassium iodide in 50 ml. of dry acetone. The chloroacetone solution had been allowed to stand for twenty-four hours pr