SU335235A1 - METHOD OF PREPARING DI-A, a'-CARBOALKOXYISOPROPYL-PEROXIDICARBOPATS - Google Patents

Description

This invention relates to processes for the preparation of new esters of peroxy acid.

A known method for the preparation of esters of paraic acid, which consists in the fact that chloroformates of the general formula

R-CO (CH2) -OCC1

II Oh

where R-alkyl, aryl, alknlaryl, is reacted with sodium peroxide in an aqueous medium at a temperature of from (-5) to (-20) ° C, followed by isolation of the target product by known methods.

A method is proposed for the preparation of new di - a, a - carboalkoxyisopropyl peroxydicarbopates, which consists in the fact that chloroformates of the general formula

About CH3 About II II II R-OC-C-OCC1 1 CH3

where R-СНз, CaHs, iso-СзНу, Н-С4Н9, H-C-Hig, cyclo-СБ 1, are subjected to interaction with sodium peroxide in an aqueous medium at a temperature not higher than -10 ° С with the subsequent release of the target product by known methods.

New peroxide compounds are active initiators of radical processes carried out at low temperatures, which distinguishes them favorably from all known peroxides.

The proposed lercarbonates ne contain at the carbon atom in the positon of hydrogen atoms, which cause the chain character of decomposition, and therefore are stable peroxide compounds. They can be stored at 20 ° C without reducing the content of active oxygen for three months. Percarbonates explode in an open flame.

In solvents, these compounds decompose at great speeds even at low temperatures. For example, half-life

di-a, a - carboethoxyisopropyl peroxydicarbonate in isopropyl alcohol at 30 ° С 3.7 hours, at 35 ° С 0.95 hours and 40 ° C 0.5 hours, and the activation energy of the reaction is 16.5 kcal / mol, evidence of lightness

peroxide decomposition in solvents.

The method of obtaining new percarbonates is extremely simple and, due to the high stability of the used cc-carboalkoxyisopropyl chloroformates, ensures high

Example. 19.45 g (0.1 g-mol} a-carboethoxy-isopropyl chloroformate) are placed into a reactor with a stirrer, a thermometer and a dropping funnel and the aqueous dispersion of freshly prepared sodium peroxide is poured on with cooling (not higher than -10 ° C) and stirring (4, 8 g, 0.06 g mol of sodium peroxide in 20 ml of water), and then stirring is continued for 0.5 hour. Then the stirrer is stopped, the upper layer is separated, washed with cold water until no alkali is present in the washings and viscous the liquid is dried over potassium carbonate.

After filtration, 12.42 g of di-a, acarbo-ethoi-isopropyl peroxydicarbonate with a basic substance content of 98.6% is obtained.

The output of 69.9% of theory, counting on the initial ss-carboethoxyisopropyl chloroformate.

Characterization of di-a, and - carboalkoxyisopropyl peroxydicarbonates of general formula

R-OC-C (CH3) 2-OSOOSO- (CH3) 2C-CO-R

IIII II1

Oo oo

where R is alkyl, is given in the table.

Subject invention

The method of producing di-a, a-carboalkoxyisopropyl peroxydicarbonate, characterized in that the chloroformates of the general formula O CH3 are:

II I II

R-OC-OSS1

 SNS

PDE R-СНз, С2Н5, «ЗО-СзНг, Я-СШд, H-CoHig,

i MKyzo-CeHu, is reacted with sodium peroxide in an aqueous medium at a temperature not higher than -10 ° C, with the subsequent isolation of the target product by known methods.