EQUILIBRIUM OF ALPHA-AMINOACETONITRILE FORMATION FROM FORMALDEHYDE, HYDROGEN-CYANIDE AND AMMONIA IN AQUEOUS-SOLUTION - INDUSTRIAL AND PREBIOTIC SIGNIFICANCE

The equilibrium constant, K-an(H2CO), for the formation of alpha-amino acetonitrile from formaldehyde, ammonia and hydrogen cyanide was evalu ated at 25 degrees C. A first estimation of K-an(H2CO) was obtained fr om extrathermodynamic relationships of the type log K-t vs Sigma sigma . The final value was then obtained from a comparison of the experime ntal and calculated pH dependences of alpha-hydroxy- and alpha-aminoac etonitrile concentrations, From these results, it appears that, after equilibrium, the ratio between the concentrations of the two precursor s glycine and hydroxyethanoic acid, is a linear function of the concen tration of free ammonia, i,e. [CH2(OH)CN] [CH2(NH2)CN] = 21[NH3] at 25 degrees C.