P- Anisic acid

Kinetic studies at 25 °C showed that for benzene, toluene, o-, m-, and p-xylene, /-butylbenzene, mesitylene, 4-chloroanisole, and p-anisic acid in 51 and 75 % aqueous acetic acid addition of small amounts of perchloric acid had only a slight effect on the reaction rate which followed equation (100). At higher concentrations of perchloric acid (up to 0.4 M) the rate rose linearly with acid concentration, and more rapidly thereafter so that the kinetic form in high acid concentration was... 

Fig. 2.71. HPLC chromatogram of the neutral (a) and acidic fractions (b) and the acid-catalysed hydrolysed product of freshly squeezed cranberry juice (c) at 280 nnm. Peaks in a 1 = ( + )-cate-chin 2 = myicetin 3 = quercetin (added as internal standard). Peaks in b 1 = anthocyanin derivative I 2 = benzoic acid 3 = p-anisic acid 4 = quercetin (added as internal standard). Peaks in c 1 = ( + )-catechin 2 = anthocyanin derivative I 3 = anthocyanin derivative II 4 = benzoic acid 5 = anthocyanin derivative III 6 = p-anisic acid 7 = myricetin 8 = quercetin. Reprinted with permission from H. Chen et al. [188].

Typical examples are listed in Table 2.1. A few oxidations are effected by RuO but in general it is too powerful an oxidant for this purpose. The system RuCyaq. NaCl-CCy Pt anode oxidised benzyl alcohol to benzaldehyde and benzoic acid and p-anisaldehyde to p-anisic acid [24], and a wide range of primary alcohols and aldehydes were converted to carboxylic acids, secondary alcohols to ketones, l, -diols to lactones and keto acids from RuOj/aq. NaCl pH 4/Na(H3PO )/Pt electrodes (Tables 2.1-2.4). The system [RuO ] "/aq. K3(S303)/Adogen /CH3Cl3 oxidised benzyhc alcohols to aldehydes [30]. The oxidation catalyst TPAP (( Pr N)[RuO ]) (cf. 1.3.4) is extremely useful as an oxidant of primary alcohols to aldehydes and secondary alcohols to ketones without... 

Note According to Davis (1943), p 170, nitration of p-anisic acid yields trinitroanisole (see under Anisole and Derivatives)... 

Tahiti vanilla (V. tahitensis Moore), which possess a different aroma, is considered as less valuable and can be distinguished from V. planifolia because of its constituents p-anisic acid and p-anisaldehyde [295[. The smaller vanillons (Vanilla pompona Schiede) are practically not available anymore. 

Small quantities of p-anisic acid are also obtained during controlled oxidation of PCME to p-anisic aldehyde. Kofifoks of Israel has been separating p-anisic acid (upto 1%) from p-anisic aldehyde. 

An easier method of production of p-anisic acid is methy-lation of p-hydroxy benzoic acid obtained as a co-product during manufacture of o-hydroxy benzoic acid (salicylic acid) via Kolbe reaction of phenol and CO2... 

Global demand of p-anisic acid is estimated to be not more than 150 tpa. The compound is used mostly as a photographic chemical and also as a dye intermediate. 

Atul has been supplying p-anisic acid approximately 50 tpa to Fuji, Japan. Atul has been now manufacturing this product from p-hydroxy benzoic acid supplied by Gujarat Organics Ltd., Ankleshwar, Gujarat state. 

Crystallise p-anisic acid from EtOH, water, EtOH/water or toluene. The S-benzylisothiuronium salt has m 189 (from EtOH). [Beilstein 10 11 91,10 111 280,10 IV 346.]... 

Treatment of tri-O-methylvitexin with hot, aqueous sodium hydroxide gives p-methoxyacetophenone and p-anisic acid, the side chain being removed from the aromatic nucleus but, with boiling aqueous barium hydroxide, an additional product, di-O-methyl-apovitexin, Ci4Hi607(0Me)2 is obtained. This ether, treated with an excess of aqueous periodic acid, gives 3-formyl-4,6-di-O-methylphloracetophenone, identical with a synthetic sample thereof. Oxidation of tri-O-methylvitexin with lead tetraacetate in acetic acid at room temperature for 5 days, or with dilute nitric acid at 100° for 1.5 hours, yields 8-formyl-tri-O-methylapigenin. These reactions, which lead to the partial structure (29) for vitexin, are summarized on p. 246. 

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