Cyanoacetaldehyde as a building block for prebiotic formation of pyrimidines

The present study uses density functional theory to investigate the possible free radical pathways for cytosine and uracil formation from cyanoacetaldehyde in the presence of urea and ammonia. Our proposed mechanisms are characterized by a smaller number of precursors and relatively lower barriers compared to previously reported reactions with other prebiotic precursors. Thus, the proposed mechanisms are more plausible in environments like prebiotic earth and present‐day Titan. Overall, this study suggests a kinetically accessible route to pyrimidine formation and will hopefully contribute toward understanding the relevance of these precursors in prebiotic reactions. Plausible free radical pathways for cytosine and uracil formation from cyanoacetaldehyde in the presence of urea and ammonia under prebiotic conditions have been proposed using density functional theory. The pathways will hopefully contribute toward understanding the relevance of cyanoacetaldehyde in prebiotic reactions.