A reaction of interaction between hexachlorenat of K2ReCl6 and a mixture of sulphuril and formic acids taken as 1:2 has been studied. it was established that during this reaction at 100–1100C temperature within 3 hours, no restoration of the salt K2ReCl6 to (CO)5Re(I)Cl was observed. Within IR-spectrum of reaction product there are missing lines of alsorption pertaining to valent fluctuations of terminal CO groups of the mentioned compound.