Copper absorption products

Decafluorobiphenyl [434-90-2] C F C F (mol wt, 334.1 mp, 68°C bp, 206°C), can be prepared by I Jllmann coupling of bromo- [344-04-7] chloro- [344-07-0] or iodopentafluorobenzene [827-15-6] with copper. This product shows good thermal stabiHty decafluorobiphenyl was recovered unchanged after 1 h below 575°C (270). Decafluorobiphenyl-based derivatives exhibit greater oxidative stabiHty than similar hydrocarbon compounds (271). Therm ally stable poly(fluorinated aryl ether) oligomers prepared from decafluorobiphenyl and bisphenols show low dielectric constant and moisture absorption which are attractive for electronic appHcations (272). 

Zinc sulfate can cause copper deficiency by inducing the production of metaUothionein in intestinal cells and thus lowering copper absorption copper deficiency can lead in turn to sideroblastic anemia (8), neutropenia, and osteopenia (9). 

The exact role of metallothionein in the intestinal absorption of copper is not well understood although zinc diminishes copper absorption by increased production of metallothionein in mucosal cells which then binds copper preferentially [4]. Excessive zinc administration was shown to indyce copper deficiency in humans [5] and to reduce copper accumulation in patients with Wilson s disease [6,7]. Thus intestinal metallothionein may have some function in maintaining copper homeostasis. After absorption, copper is immediately transported in plasma bound to albumin and to amino acids [8]. 

High purity acetaldehyde is desirable for oxidation. The aldehyde is diluted with solvent to moderate oxidation and to permit safer operation. In the hquid take-off process, acetaldehyde is maintained at 30—40 wt % and when a vapor product is taken, no more than 6 wt % aldehyde is in the reactor solvent. A considerable recycle stream is returned to the oxidation reactor to increase selectivity. Recycle air, chiefly nitrogen, is added to the air introducted to the reactor at 4000—4500 times the reactor volume per hour. The customary catalyst is a mixture of three parts copper acetate to one part cobalt acetate by weight. Either salt alone is less effective than the mixture. Copper acetate may be as high as 2 wt % in the reaction solvent, but cobalt acetate ought not rise above 0.5 wt %. The reaction is carried out at 45—60°C under 100—300 kPa (15—44 psi). The reaction solvent is far above the boiling point of acetaldehyde, but the reaction is so fast that Httle escapes unoxidized. This temperature helps oxygen absorption, reduces acetaldehyde losses, and inhibits anhydride hydrolysis. 

Dutch State Mines (Stamicarbon). Vapor-phase, catalytic hydrogenation of phenol to cyclohexanone over palladium on alumina, Hcensed by Stamicarbon, the engineering subsidiary of DSM, gives a 95% yield at high conversion plus an additional 3% by dehydrogenation of coproduct cyclohexanol over a copper catalyst. Cyclohexane oxidation, an alternative route to cyclohexanone, is used in the United States and in Asia by DSM. A cyclohexane vapor-cloud explosion occurred in 1975 at a co-owned DSM plant in Flixborough, UK (12) the plant was rebuilt but later closed. In addition to the conventional Raschig process for hydroxylamine, DSM has developed a hydroxylamine phosphate—oxime (HPO) process for cyclohexanone oxime no by-product ammonium sulfate is produced. Catalytic ammonia oxidation is followed by absorption of NO in a buffered aqueous phosphoric acid... 

Next, reductive amination (step 4 in scheme 1) was exchanged with copper catalyzed palladium coupling (step 2 in scheme 1). Atomic absorption analysis for palladium in RWJ-26240 samples prepared by scheme 2 indicated that the level of palladium was reduced to an acceptable level. This improvement may be due to the two reduction steps subsequent to the use of palladium in scheme 2.177 The final major modification to the reaction scheme was the substitution of NaBH4 for NaBH3CN. The yield of product (60%) was determined by HPLC (Method 2). Reductive alkylation with formalin/NaBH4 afforded a pharmaceutically acceptable drug substance. 

Sulphuric acid is the largest volume chemical in the world with an annual production of about 180 mill, t/year which is used primarily for phosphate fertilizers, petroleum alkylation, copper ore leaching and in smaller quantities for a number of other purposes (pulp and paper, other acids, aluminium, titanium dioxide, plastics, synthetic fibres, dyestuffs, sulphonation etc.). The major sulphur sources for sulphuric acid production are sulphur recovered from hydrocarbon processing in the refineries and from desulphurisation of natural gas, SO2 from metallurgical smelter operations, spent alkylation acid, and to a minor extent mined elemental sulphur and pyrites. A simplified flow sheet of a modem double-absorption plant for sulphuric acid production from sulphur is shown in Fig. 1. 

J. J. van Laar has shown how the form of the vap. press, curves of a liquid mixture can furnish an indication, not a precise computation, of the degree of dissociation of any compound which maybe formed, on the assumption that the different kind of molecules in the liquid—12, Br2, and IBr—possess partial press, each of which is equal to the product of the vap. press, of a given component in the unmixed state and its fractional molecular concentration in the liquid. It is assumed that in the liquid, there is a balanced reaction 2IBr I2-)-Br2, to which the law of mass action applies, where K is the equilibrium constant, and Clt C2, and C respectively denote the concentration of the free iodine, free bromine, and iodine bromide. From this, P. C. E. M. Terwogt infers that at 50 2°, K for the liquid is 7j and that for iodine monobromide about 20 per cent, of the liquid and about 80 per cent, of the vapour is dissociated. That the vapour of iodine monobromide is not quite dissociated into its elements is evident from its absorption spectrum, which shows some fine red orange and yellow lines in addition to those which characterize iodine and bromine. In thin layers, the colour of the vapour is copper red. 0. Ruff29 could uot prove the formation of a compound by the measurements of the light absorption of soln. of iodine and bromine in carbon tetrachloride. 

---