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): CC(C)(C)OC(=O)n1ccc2c(-c3cc(C(=O)c4nc5ccc(N6CCC(O[Si](c7ccccc7)(c7ccccc7)C(C)(C)C)CC6)nc5[nH]4)ccc3C#N)cncc21 .
assistant