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
To synthesis <molecule_2d>, what are the possible reactants? Write in the SMILES representation.
user
COc1ccc2c(c1)[nH]c1c(C(N)=O)ncc(-c3cccc(N4Cc5ccc(Cl)cc5C4=O)c3C)c12
assistant