Perkin s synthesis

This formula was confirmed hy Haworth and Perkin s synthesis of a-flZZocryptopine from herherine, the first application of a process, of which examples have heen given already in the syntheses of cryptopine (p. 298) and protopine (p. 301) hy the same authors. Anhydrotetrahydromethyl-herherine (I cf. hase (a), p. 346) in dry chloroform was added to a solution of perhenzoic acid in ether cooled helow 5°. The amine oxide, C21H23O5N (II), separated as an oil, which after shaking with sodium hydroxide solution, solidified and was crystallised from water in slender prisms, m.p. 135°. It was dissolved in acetic acid, hydrochloric acid added, the mixture heated in boiling water for an hour and the hase precipitated hy addition of potassium hydroxide. The precipitate was dissolved in methyl alcohol, ether added, the alcohol washed out with water and the ethereal... 

Coumarin was first produced synthetically by Perkin. He made it by heating salicylic aldehyde, CgH (OH)i(COH), acetic anhydride, and sodium acetate. The whole solidifies to a crystalline mass, from which, on treatment with water, an oil separates containing coumarin and aceto-coumaric acid. This acid on heating is decomposed into acetic acid and coumarin, so that the product of distillation is principally coumarin. Perkin s synthesis proceeds according to the following equation —... 

Acetyl chloride (54 g. =075 mole) is allowed to run drop by drop from a tap funnel on to 80 g. of finely powdered anhydrous sodium acetate prepared in the manner described below. When about half of the chloride has been added the experiment is interrupted for a short time in order to stir the pasty mass of material with a bent glass rod, the lower end of which has been flattened. The rest of the acetyl chloride is then run in at such a rate that none passes over unchanged. The anhydride is now distilled from the residual salt by mean of a luminous flame kept constantly in motion. Complete conversion of the last traces of unchanged acetyl chloride to acetic anhydride is attained by adding 3 g. of finely powdered anhydrous sodium acetate to the distillate, which is finally fractionally distilled. Boiling point of acetic anhydride 138°. Yield 55-60 g. Use for acetylation, in Perkin s synthesis (Chap. V. 8, p. 232), preparation of acetophenone (Chap. IX. 3 6, p. 346). 

From salicylaldehyde and sodium acetate by Perkin s synthesis coumarin is formed. (Formulate )... 

Derivatives of Menthene.— The most important alcohols and ketones derived from the menthene unsaturated group of terpenes are terpineol, di-hydro carveol, di-hydro carvone and pulegone. The first one, the alcohol terpineol, occurs in its dextro form in cardamon oil and marjoram oil, in its leoo form in neroU oil and in its inactive form in cajeput oil. The constitution is proven by Perkin s synthesis from As-tetra-hydro para-toluic acid by means of the Grignard reaction. 

Alkylation of malonic ester. This alkylation can be done with a solution of sodium ethoxide in ethanol and requires one mole of reagent per alkyl group introduced. An example is Perkin s synthesis of diethyl cyclobutane-1,1-dicarboxylate by alkylation with triraethylene chlorobromide. When trimethylene dibromide was... 

Tyrosine has been prepared by a number of interesting methods one of these involves the condensation of p-hydroxy-benzaldehyde and hippuric acid, C6H5CO.NH.CH2COOH, by a reaction similar to that which takes place in Perkin s synthesis. 

Utilising the formulae assigned to the two products of hydrolysis of narcotine, viz., hydrocotarnine and opianic acid, Roser constructed a formula for the alkaloid which has been confirmed by Perkin and Robinson s synthesis of narcotine from meconin and cotarnine. ... 

The next milestone in the development of organic synthesis was the preparation of the first synthetic dye, mauveine (aniline purple) by Perkin in 1856 Perkin, 1856, 1862). This is generally regarded as the first industrial organic synthesis. It is also a remarkable example of serendipity. Perkin s goal was the synthesis of the antimalarial drug quinine by oxidation of N-allyl toluidine (Fig. 2.4). 

Chittari, P. Jadhav, V. R. Ganesh, K. N. Rajappa, S. Synthesis and Metal Complexation of Chiral 3-Mono- or 3,3-Bis-allyl-2-hydroxypyr-rolopyrazine-l,4-diones, J. Chem. Soc. Perkin Trans. 1 1998, 1319. 

B. S. Synthesis of isochroman-3-ylacetates and isochromane-y-lactones through rearrangement of aryldioxolanylacetates./. Chem. Soe. Perkin Trans. 1 1998, 3949-3956. 

Fig. 13.38. Perkin s first cyclopropane synthesis via a malonic ester synthesis.

Organic synthesis followed a different line of evolution. A landmark was Perkin s serendipitous synthesis of mauveine (aniline purple) in 1856 [26] which marked the advent of the synthetic dyestuffs industry, based on coal tar as the raw material. The present day fine chemicals and pharmaceutical industries evolved largely as spin-offs of this activity. Coincidentally, Perkin was trying to synthesise the anti-malarial drug, quinine, by oxidation of a coal tar-based raw material, allyl toluidine, using stoichiometric amounts of potassium dichromate. Fine chemicals and pharmaceuticals have remained primarily the domain of... 

Akimoto, H., Imamiya, E., Hitaka. T., Nomura, II., and Nishimura. S Synthesis of queuine, base of naturally occurring hyper-modified nucleoside (queuosinc) and Us analogues, 7. Chem. Soc. Perkin Trans. I, 1637, 1988. 

Cinnamic Acid by Perkin s Reaction.—Cinnamic acid has the constitution assigned to it above as is proven by the following synthesis from benzaldehyde by condensation with sodium acetate in the presence of acetic anhydride. 

---