Guaiacol benzoate

Nencki introduced salol in 1886 and. so pre.sented to the science of therapy the "salol principle." In salol. two toxic sub.stances (phenol and salicylic acid) were combined into an e.ster that taken internally slowly hydroly/es in the intestine to give the antiseptic action of its components. This type of ester is referred to as a full. salol or true salol when toth components of the ester are active compounds. Examples are guaiacol benzoate. /3-naphthol benzoate, and salol. The salol principle can be applied to esters in which only the alcohol or the acid is the toxic, active or corrosive portion this type is called a partial salol. Examples of partial sulols that contain an active acid arc ethyl salicylate and methyl salicylate. Examples of partial sulols that contain an active phenol are creosote carbonate, thymol carbonate, and guaiacol carbonate. Althtxigh many. salol-typc compounds have been prepared and used tu. some extent, none is presently... 

Phenols can be acylated (guaiacol benzoate, pheny-lacetate, or valerate) or alkylated (guaifenesin, guaiapate) (Figure 41.11). 

Preparation from 3-(benzoyloxy)-4-methoxy-benzophenone (SM) (m.p. 95°5-96°5) [686] by saponification [162] with sodium hydroxide in refluxing ethanol (good yield) [273,686] or with potassium hydroxide in refluxing methanol (98%) [687], SM was obtained by Friedel-Crafts acylation of guaiacol benzoate with benzoyl chloride in the presence of zinc chloride [162,273,686] or in the presence of stannic chloride in nitromethane for 1 h at 20° (82%) [687],... 

Although benzoate is generally metabolized by oxidative decarboxylation to catechol followed by ring cleavage, nonoxidative decarboxylation may also occur (1) strains of Bacillus megaterium transform vanillate to guaiacol by decarboxylation (Crawford and Olson 1978) and (2) a number of decarboxylations of aromatic carboxylic acids by facultatively anaerobic Enterobacteri-aceae have been noted in Chapter 4, Section 4.3.2. 

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