CC[C@H](C)C(C(=O)OC(C)(C)C)n1cc(-c2cc(C(=O)N3CCN(C(=O)OC(C)(C)C)CC3)cc(-c3cn([C@@H](CCCCNC(=O)OC(C)(C)C)C(=O)OC)nn3)c2)nn1
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?