In optical resolution of amino acids, the usefullness of metal complexes is one of the interesting subjects and is now asking its possibility. Here, the asymmetric reactions for metal-amino acid complexes are reviewed from a viewpont of optical resolution of amino acids, and our study for the optical resolution of amino acids with labile cobalt(III)-Schiff-base complex is introduced.
A new synthetic method of pyrimidines by the reaction of α, α-diamino compounds such as guanidine, amidine, thiourea and urea with O-heterocyclic compounds having oxyvinyl-carbonyl or oxyvinylnitrile moiety in the hetero-aromatic ring is described. The O-heterocyclic compounds-considered as “masked ketone” -which play a role as “three-carbon fragment” for the formation of pyrimidines in the above reaction are classified into the following three groupes : (1) benzofurans substituted at position 3 by electron-attracting group, (2) benzo-γ-pyrones, and benzo-α-pyrones, and (3) γ-pyrones. Thus from these oxygen heterocycles were obtained the new derivatives of 5-(2-hydroxyphenyl) pyrimidine, 4- (2-hydroxyphenyl) pyrimidine, and 4-acetonylpyri midine, respectively. The influences of the three factors on the formation of pyrimidines are discussed : (1) structure of the starting oxygen heterocycle, (2) reactivity of the α, α-diamino compounds as nucleophilic reagent, and (3) reaction conditions used.
The reactions of N-phenyliminodiacetic anhydride with hydrazine derivatives were carried out. The mono hydrazides thus obtained were cyclized by fusion or by heating with acetic anhydride, giving 1-amino derivatives of 4-phenyl-2, 6-piperazinedione.
Liquid phase catalytic hydrogenolysis of straight-chain 1, 2-epoxyalkanes to primary alcohols was studied over cobalt-phosphorus catalyst under 40 kg/cm2 of initial hydrogen pressure and 100190°C. Two types of catalysts, supported on alumina (Co-P-Al2O3) and unsupported (Co-P), were prepared by the reduction of cobaltous phosphate with hydrogen at an elevated temperature. Optimal temperature for the reduction was 650°C. 1, 2-Epoxyoctane was hydrogenolyzed in n-hexane with Co-P-Al2O3 to mainly octanols accompanied with n-octane and a small amount of 2-octanone. The selectivity of 1-octanol in octanols was about 93%. In the case of the catalytic hydrogenolysis of 1, 2-epoxyhexane in ethanol, the solvolysis to ethoxyhexanols, which occurred to the considerable extent over Co-P-Al2O3, was depressed over Co-P catalyst. It was shown that the alumina in the catalyst increased the solvolysis product.
The original reports of organic photochemistry published in 1975 were abstracted from selected seventeen primary journals and reviewed. More than 80% of over the three hundred reports dealt with the photochemical reaction of carbonyl, olefinic and arylic groupings. The singlet oxygen (dye-sensitized oxygen) was also subjects of a lot of investigators.
The first commercial manufacturing process of aniline was developed by Bechamp and Perkin based on the reduction of nitrobenzene under the presence of iron powder and acid in the 1850's. Generally speaking, we may well say that what sort of manufactuning processes are employed at a certain era depends on various factors such as market size of the product which influences the scale of the production facilities, the availability of raw materials, equipment and the control system at such time. In the field of aniline production technology, the amination process of chlorobenzene was developed in the 1930's which was followed by the invention of the catalytic hydrogenation of nitrobenzene in 1950's after world war II. The latter is an innovative technology and was applied to a number of commercial plants in the form of various reaction technologies such as vapour phase, liquid phase, fixed catalyst-bed, fluidized catalyst-bed. In the 1960's, the amination process of phenol was invented and the first commercial plant in the world based on such process was built in Japan. However, it appears that for the manufacture of aniline, both old and new processes are utilized in the world today as is evidenced by the fact that all the above mentioned processes except the amination process of chlorobenzene are still used. The basic reason for this phenomenon is that each process has its own advantages either in raw material supply sources or reaction conditions or utilization of by-products and all of them can be competitive in one way or another with respect to the yields, product quality, etc. Thus, aniline manufactures today can choose, out of the three processes, the most advantageous process which suit best their local conditions such as available raw material sources and product quality requirements and marketing capability.