This paper focuses on non linear control of non isothermal Continuous Stirred Tank Reactors (CSTRs). The model of the CSTR is thermodynamically consistent in order to apply the control strategy based on the concavity of the entropy function and the use of thermodynamic availability as Lyapunov function. More precisely the stabilization problem of continuous chemical reactors is addressed operated at an unstable open loop equilibrium point. The chosen control variable is the jacket temperature. In this paper we propose a state feedback strategy to insure asymptotic stability with physically admissible control variable solicitations. Theoretical developments are illustrated on a first order chemical reaction.