| abstract |
1,146,925. Preparation of alkylsalicylic acids. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 28 June, 1967, No. 29775/67. Heading C2C. [Also in Division C5] (a) 1 mole of salicylic acid is alkylated at 60-150‹ C. with 2À5 moles of C 14 -C 18 olefins using 1-2 moles of BF 3 as catalyst to yield a mixture of 3-alkyl, of 5-alkyl, and of 3,5- dialkyl salicylic acids; (b) 1À3 moles of para or ortho cresol is alkylated at 100-250‹ C; with 0À5 to 1 mole of C 14 -C 18 olefins using 1-10% w. of acid clay as catalyst and the. alkylphenols formed converted to 3-alkyl-5-methylsalicylic acid or 3- methyl-5-alkyl salicylic acid respectively; (c) 1 mole of phenol is alkylated at 100- 250‹ C. with 2-4 moles of cetene using 1-10% of acid clay as catalyst and the alkylphenols formed converted to a mixture containing 3- cetyl, 5-cetyl, and 3,5-dicetyl salicylic acids. The alkylphenols may be converted to alkylphenates by alcoholic caustic soda and these can be carboxylated with CO 2 at 140‹ C. and 10-30 atmos. The alkylsalicylates formed can be hydrolysed to the acids with 30% sulphuric acid and converted to normal or superbasic calcium salts. |