Peroxides mixed, synthesis

In many instances, beginning a synthesis with quinoline N-oxide [1613-37-2] faciHtates the preparation of difficult compounds. Quinoline is converted to the N-oxide using hydrogen peroxide in acetic acid, and later reduced to the substituted quinoline. Warm mixed acid gives 4-rutroquinoline... 

After synthesis, the modified carborane-siloxane gums were fabricated into shaped components using standard siloxane vulcanization and fabrication technology. Di-chlorobenzyl peroxide (1% by wt) was used as the cross-linking agent and mixed into the polymer formed in scheme 7. Shaped rubber components were readily prepared by compression molding operations at 70°C. Postcure operations were typically at 120°C for 24 hours. 

SCHEME 32. Synthesis of mixed dialkyl peroxides from Inflates... 

A new method for synthesis of dialkyl peroxides is based on the novel peroxide transfer reaction between Ge or Sn peroxides and alkyl triflates. Mixed diaUcyl peroxides are obtained from the reaction of bis(butyltin)germyl peroxide with alkyl triflates. 

For synthesis of mixed trimeric peroxides (e.g., 59), see Sanderson Zciler Synthesis 1975, 388 Paul Story Busch Sanderson J. Org. Chem. 1976, 41. 1283. 

Thromboxanes, like prostaglandins, contain a ring of five or six atoms the pathway from arachidonate to these two classes of compounds is sometimes called the cyclic pathway, to distinguish it from the linear pathway that leads from arachidonate to the leukotrienes, which are linear compounds (Fig. 21-16). Leukotriene synthesis begins with the action of several lipoxygenases that catalyze the incorporation of molecular oxygen into arachidonate. These enzymes, found in leukocytes and in heart, brain, lung, and spleen, are mixed-function oxidases that use cytochrome P-450 (Box 21-1). The various leukotrienes differ in the position of the peroxide... 

The synthesis of mixed peroxides formed from /-butyl hydroperoxide and carbon-centred radicals has been studied. The reactions were strongly effected by solvents as well as catalytic amounts of Cun/Fem. The kinetic data suggest that the conditions for the Ingold-Fischer persistent radical effect are fulfilled in these cases.191 The use of Cu /Cu" redox couples in mediating living radical polymerization continues to be of interest. The kinetics of atom-transfer radical polymerization (ATRP) of styrene with CuBr and bipyridine have been investigated. The polymer reactions were found to be first order with respect to monomer, initiator and CuBr concentration, with the optimum CuBr Bipy ratio found to be 2 1.192 In related work using CuBr-A-pentyl-2-... 

Independent Variables. Simultaneous synthesis of two polymer networks is a complex process. Many independent variables are available for study and not all could be explored in a limited investigation. The emphasis in the present study centers on those variables whose predominant effect is to influence the relative rates or gelation times of the reactions. Three independent variables were selected (a) the concentration of di-tert-butyl peroxide initiator was changed to vary the rate of polymerization of n-butyl acrylate (b) the epoxy mix was allowed to prereact for different lengths of time before the acrylate mix was added, and (c) the amount of DEGDM added to the acrylate mix was varied to control the gel time of the acrylate without significantly affecting its rate of polymerization. 

In general, the synthesis of polyphosphazene polymers is unique in that, in theory, an infinite number of polymers with a variety of properties can be derived from the common polymeric intermediate, poly(dichlorophosphazene) (PNCI2), by replacing the chlorines with different nucleophiles. If the polydichlorophosphazene precursor is reacted with the sodium salts of trifluoroethanol and a mixed fluorotelomer alcohol, a poly(fluoroaIkoxyphosphazene) elastomer (FZ elastomer) is obtained. It contains a small amount of an unsaturated substituent as a curing site. The polymer is a soft gum, which can be compounded with carbon blacks and fillers and cured with sulfur or peroxides or by radiation. 

Peroxy acids. Konen and Silbert have developed a mild, general synthesis of peroxy acids entailing first acylation of silver diethyl phosphate in ether solution followed by perhydrolysis of the mixed anhydride with hydrogen peroxide (98%... 

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