You are a chemist. Now you are given a product molecule. Please predict the the reactant molecules of the reaction.
The reaction equation has the following format:
```
reactant1.reactant2. ... .reactantN>>product
```
Your task is to predict the structure representation of the reactant molecule. We provide the SMILES of the reactants.
system
Given the following product, please provide possible reactants. <molecule_2d>
user
Possible reactant(s): CCCCOc1nc(N)c2nc(OC)n(CCCC3CCCCN3C(=O)OCc3ccccc3)c2n1 .
assistant