Active hydrogen compounds conversion

Reaction of 1,3-dienes tith active hydrogen compounds. The catalyst resulting from the combination of nickel bromide and a dialkoxyphenylphosphine effects condensation of 1,3-dienes with active hydrogen compounds to give butenyl and octadienyl adducts.1 Thus the reaction of morpholine (1, 0.05 mole) with butadiene (0.15 mole) in the presence of nickel bromide (1 mmole) and diisopropoxyphenylphosphine (1.1 mmole) at 100° for 30 min. gives a 79% conversion to the adducts (2), (3), (4), and (5). 

The complex formed between diethyl azodicarboxylate and triphenylphosphine is a very useful reagent for condensation reactions. The reaction of alcohols with phthalimides, in the presence of diethyl azodicarboxylate and triphenylphosphine, resulted in the formation of the corresponding AT-alkylphthalimide in good yield. The reaction proceeds stereospecifically with complete inversion, as shown by conversion of (5 )-(+)-2-octanol to )-2-octylamine, isolated by treatment of the initially formed phthalimide with hydrazine hydrate. Condensation between alcohols and other active-hydrogen compounds using the same reagents has also been described (Scheme 1). Phosphorylation of alcohols by initial activation... 

Active hydrogen compounds such as alcohols, thiols, amides, urethans, and sulfonamides can be alkylated by N-vinyl-amides, -urethans, or -sulfonamides in high yields. A one-step conversion of ar. nitro compounds to isocyanates has been reported Aliphatic isothiocyanates can be prepared from amines and carbon disulfide with dicyclohexylcarbodiimide under remarkably mild conditions... 

The catalytic hydrogenation of benzene has been carried out as a model reaction to increase the hydrogenated cyclic compounds from aromatics. Catalyst samples containing nickel on different supports were prepared and tested. It was found that a-Al203 supported nickel showed the best activity for benzene conversion reaction. Nickel metal area, its dispersion and nickel crystal size were determined. The best activity is obtained with 40% nickel concentration (as oxide) and at the optimum nickel crystallite size of 196A° and optimum metal area of 10.8m2/g. 

B. Decline of catalyst activity for reasons connected with the synthesis itself, for example sintering, adsorption of high molecular synthetic products (waxes, etc.), excessive carbon formation, salts, produced on the catalyst surface by conversion with synthetic acids, and formation of volatile carbonyls and carbonyl hydrogen compounds. 

The range of most convenient hydrophobicity of organic compounds for reversed-phase (RP) HPLC separation may be estimated approximately as —1 < log P < + 5 (log P is the logarithm of the partition coefficient of the compound being characterized in the standard solvent system 1-octanol/water). Highly hydrophUic substances with log P < —1 need a special choice of analysis conditions, e.g., introduction of ion-pair additives into the eluents. Another approach is their conversion to more hydrophobic derivatives by the modification of functional groups with active hydrogen atoms. 

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