Crystalline derivatives preparation secondary

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. 

Dimethylamino-l,3-diphenyl-l,3,2-diazaphospholane (102) reacts with primary and secondary alcohols to give crystalline derivatives (103) useful for characterization purposes more interesting is their use to convert alcohols to alkyl halides. Several new ligands for catalysts in asymmetric redox reactions have been prepared. These include (104) and (105), the Rh complexes of which have been used successfully in asymmetric hydrogenations, and (106), which however was inferior to diop in hydrogenation and hydroformylation reactions. ... 

In addition to these physical studies at the Bureau, Tipson was able to return to his synthetic interests, both alone and in collaboration with other staff members. He was especially pleased to prepare D-talose in crystalline form, an accomplishment that had eluded Emil Fischer. Pursuing his longstanding interest in the reaction of sulfonic esters with iodide and following an earlier observation that the tetratosyl ester of erythritol is converted into butadiene by the action of sodium iodide and zinc, he demonstrated (with A. Cohen) that nonterminal unsaturation may be conveniently introduced into alditol derivatives by reaction of contiguous secondary sulfonates with sodium iodide and zinc dust in boiling A.A-dimethylformamide. This Tipson-Cohen reaction subsequently proved of great utility in other hands for the conversion of more complex carbohydrate structures into vicinal dideoxy derivatives. 

Secondary amines can be prepared from the primary amine and carbonyl compounds by way of the reduction of the derived Schiff bases, with or without the isolation of these intermediates. This procedure represents one aspect of the general method of reductive alkylation discussed in Section 5.16.3, p. 776. With aromatic primary amines and aromatic aldehydes the Schiff bases are usually readily isolable in the crystalline state and can then be subsequently subjected to a suitable reduction procedure, often by hydrogenation over a Raney nickel catalyst at moderate temperatures and pressures. A convenient procedure, which is illustrated in Expt 6.58, uses sodium borohydride in methanol, a reagent which owing to its selective reducing properties (Section 5.4.1, p. 519) does not affect other reducible functional groups (particularly the nitro group) which may be present in the Schiff base contrast the use of sodium borohydride in the presence of palladium-on-carbon, p. 894. 

JCS(P1)1171] and Sung (81CC1089 82JOC3623) found that these 1,2,4-triazole derivatives of uridine can be readily prepared at room temperature with excess 1,2,4-triazole and phosphoryl chloride and triethylamine or with 0-chlorophenyldi-(l//-l,2,4-triazol-l-yl)phosphine oxide in acetonitrile. These stable, often crystalline 1,2,4-triazole derivatives react readily with aqueous ammonia and primary or secondary amines at room temperature to afford the corresponding cytidines in high yields. 

Optically active alkylphenylarsinous acid esters can be prepared by treating chloro-alkylphenylarsines with alcohols in the presence of ( —)-brucine or (— )-iV,iV-diethyl-a-methylbenzylamine. Secondary haloarsines react with the lithium derivative of (— )-cinchonidine to give the crystalline cinchonidine esters of arsinous acids 131 and 132 Another route to optically active arsinous acid esters is given in Scheme 14 ... 

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... 

For the identification and subsequent characterization of hydroxy compounds as well as primary and secondary amines, by preparing their crystalline acetyl derivatives. 

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]. 

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