Crystalline derivatives preparation tertiary

The above reactions wiU serve to place an amine into its class— primary, secondary or tertiary. For complete characterisation, a crystalline derivative should be prepared. A large number of derivatives of amines are avaUable the foUowing wiU be found useful. 

The beanlike seeds of the trees and shrubs of the genus Erythrina, a member of the legume family, contain substances that possess curare-like activity. The plants are widely distributed in the tropical and subtropical areas of the American continent, Asia, Africa, and Australia, but apparently they are not used by the natives in the preparation of arrow poisons. Of 105 known species, the seeds from more than 50 have been tested, and all were found to contain alkaloids with curariform properties. Erythroidine, from E. americana, was the first crystalline alkaloid of the group to be isolated. It consists of at least two isomeric alkaloids, a and P-erythroidine both are dextrorotatory. Most experimental and clinical study has centered on the b form because it is more readily obtainable in pure state. P-Erythroidine is a tertiary nitrogenous base. Several hydrogenated derivatives of p-erythroidine have been prepared of these, dihydro-P-erythroidine has been studied most carefully and subjected to clinical trial. Conversion of P-erythroidine into the quaternary metho salt (p-erythroidine methiodide) does not enhance, but rather almost entirely, abolishes its curariform activity this constitutes a notable exception to the rule that conversion of many alkaloids into quaternary metho salts results in the appearance of curare-like action. 

Tris(pyrazolyl)hydroborato magnesium alkyl derivatives [Tp ]MgR are readily prepared by the reactions of [M][Tp ] (M = K, Tl) with solutions of the appropriate dialkyl-magnesium [Eq. (3) 14-17]. The reaction is very general and a series of primary, secondary tertiary, vinyl, and phenyl derivatives have been obtained, as illustrated in Table 1. The magnesium alkyl complexes [Tp ]MgR are all white crystalline solids that are soluble... 

Allophanic acid (ureidoformic acid, NH2CONHCOOH) is an elusive compound which is known only in the form of its derivatives. Ester-like organic allophanates have been prepared from primary, secondary, and tertiary alcohols and from phenols [39], whereas inorganic allophanate salts are unstable and easily hydrolyzed by H2O to CO2, urea, and carbonate [40]. The first two crystalline complexes containing host lattices built of urea molecules and allophanate ions were prepared and structurally characterized in 1995 [5h]. 

A particularly useful application of the crown mediated ester synthesis is in the preparation of phenacyl esters [21, 22]. The crown catalyzed reaction of potassium carboxylates with a,4-dibromoacetophenone yields derivatives which are usually crystalline and which can be readily detected by uv spectroscopy [23]. Moreover, the phenacyl ester is a useful protecting group which can be removed under mild conditions [24]. Phenacyl ester formation has also been catalyzed by tertiary amines [5]. Examples of the condensation according to equation 6.7 are given in Table 6.6. 

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