Anhydroberberilic acid

Berberilic acid, CgoHjgOgN, m.p. 177-82°, is dibasic, and furnishes a dimethyl ester, m.p. 173°. When heated to about 180°, the acid passes into ANHYDROBERBERiLic ACID, CjgHjjOgN, colourless needles, m.p. 236°, soluble in alkali carbonate solutions with the formation of berberilates. When ammonium berberilate is dried under reduced pressure, a molecular proportion of ammonia is lost with the formation of the ammonium salt of the anhydro-acid, from which other salts, and the methyl ester, m.p. 178°, have been obtained. Berberilic acid is hydrolysed by hot dilute sulphuric acid to hemipinic acid (I) and oi-aminoethylpiperonylic acid (II), large tabular crystals, m.p. 180-2°. Berberilic acid is therefore represented by (III). 

Anhalonium alkaloids, pharmacology, 160 Anhalonium spp., 154 Anhydroberberilic acid, 332 Anhydroecgonine, 97 Anhydrolupinine, 120 Anhydroxatine, 770 Anisomeles malabaTica, 779 Af-(2-p-Anisylethyl)-AT-methyl-cinnamide, 330, 631 Annona anibotay, 371 Annotinine, 752, 753, 755 Anodmine, 47 Anolobine, 317... 

Alternatively, treatment of oxybisberberine with pyridine hydrochloride in pyridine led to oxidative scission, and the nature of the products was dictated by the nucleophiles present and by the pH of the medium during the work-up. When the reaction was quenched with methanolic and aqueous acids, the products were the 8,13-dioxoberbines 44 and 45, respectively. These compounds undergo rapid, reversible, interconversion in acidic media through an immonium quinoid species. On the other hand, neutral work-up with buffered systems gives rise to the aporhoeadane 46, which is also produced rapidly but irreversibly on treatment of 45 with ammonium hydroxide. Alkaline work-up invariably produced as the major product Perkin s anhydroberberilic acid 47 as well as its solvolysis product noroxyhydrastinine (see Scheme 19.7). 

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