Pictet

The reaction conditions applied are usually heating the amine with a slight excess of aldehyde and a considerable.excess of 2d-30hydrochloric acid at 100 °C for a few hours, but much milder ( physiological ) conditions can be used with good success. Diols, olefinic double bonds, enol ethers, and glycosidic bonds survive a Pictet-Spengler reaction very well, since phenol and indole systems are much more reactive than any of these acid sensitive functional groups (W.M. Whaley, 1951 J.E.D. Barton, 1965 A.R. Battersby, 1969). 

Another procedure for obtaining a-aminoketones is by reduction of a-nitrosoketones in the presence of the required carboxylic acid. Acylaminoketones are prepared either by reacting acids with the chlorhydrate of a-aminoketones according to the method of Pictet and Gauss (41) or by the action of acid anhydrides upon a-amino acids (550). 

The Pictet-Gams method involves the cyclization of P-hydroxy- or P-methoxy- P-phenethylamides, and produces the isoquinoline derivative rather than the reduced form. A further extension of method is based on a metboxyetbyl amine. 

Enthalpies of vaporization, at the normal boiling point, T, can be estimated roughly with the simple rule of Pictet and Trouton (19) which... 

It is equivalent to say that entropy of vaporization is a constant value for non-associating Hquids. Associating Hquids, eg, ammonia, water, methanol, and ethanol, do not obey the rule of Pictet and Trouton. Despite its simplicity, the Pictet-Trouton view of Hquid vaporization (19) is an exceUent example of the many rules of thumb that have been useful aids in engineering calculations for decades (5,7,8,9,21). However, proper appHcation requires an understanding of the physical reasoning behind each rule. 

LEUCKARDT PICTET HUBERT Ph nanlhndlne synthesis AmUation of aryls by isocyanates (Leuckardt) or by amides (Pictel-Hubert), catalyzed by Lews acids and leading to phenanitwldinas. 

PICTET HUBERT GAMS Isoquinollne Synthesis Isoqulnolmes Irom phenethylamides phenanthndine Iroin o acylammobiaiyl with POCI3 SrCU ... 

PICTET SPENGLER Isoquinollne Synthesis Isoquinoline synthesis ol phenethylammes and pyruvic acid derivatives... 

The best source of the alkaloids is commercial nicotine or the concentrated tobacco extracts, used as horticultural insecticides. The average alkaloidal content of tobacco leaf is about 4,- and does not as a rule exceed 6, per cent. In 1,026 parts of the total alkaloids of Kentucky tobacco, Pictet and Rotschy found nicoteine 20, nicotimine 5 and nicotelline 1, the rest being nicotine, but, as Markwood has pointed out. 

Syntheses of Nicotine. Pictet and Cr pieux found that 3-aminopyridine mueate on dry distillation yielded l-(3-pyridyl)pyrrole (I), and this, in accordance with the usual behaviour of such pyrrole derivatives, transfers its pyridyl substituent from the 1- to the 2-position at a red heat giving 2-(3-pyridyl)pyrrole (II), which is nomieotyrine. The potassium derivative of this reacts with methyl iodide to form l-methjd-2-(3-pyridyl)-pyrrole methiodide, which is identical with nieotyrine methiodide (III), and on distillation with lime yields nieotyrine (IV Cl — CH). For a re-investigation of this synthesis see Spath and Kainrath. ... 

The tetrahydronicotyrine produced by these methods is identical with dZ-nicotine, and this, by crystallisation of the d-ditartrate, was separated into d- and Z-nicotine. The salient steps in Pictet s original synthesis may be represented as follows —... 

Comparison of these results indicates identity of the two substances isolated independently by Orekhov and Ehrenstein, but Spiith and Kesztler have suggested that Pictet s nicoteine and Ehrenstein s base, consisted of impure Z-anatabine (p. 46). In this connection it may be noted that Ehrenstein s base was laevorotatory in acid solution, whereas Salts of anabasine are dextrorotatory. These authors have themselves isolated Z-anabasine from tobacco. The identity of synthetic 2-(3 -Pyridyl)piperidine with dZ-anabasine seems to have been definitely established. Anabasis aphylla is the source of the anabasine raanufac-... 

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