2-(4-Bromo­phen­yl)-1-ethyl-1H-1,3-benzodiazole

In the title compound, C15H13BrN2, the benzimidazole group is almost planar, as indicated by the dihedral angle of 2.6 (3)° between the best planes through the benzene and imidazole rings. The best plane through the attached benzene makes an angle of 44.5 (2)° with the best plane through the benzimidazole system. C—H⋯π inter­actions are observed in the crystal structure

Boosting Transferability of Targeted Adversarial Examples via Hierarchical Generative Networks

Transfer-based adversarial attacks can effectively evaluate model robustness in the black-box setting. Though several methods have demonstrated impressive transferability of untargeted adversarial examples, targeted adversarial transferability is still challenging. The existing methods either have low targeted transferability or sacrifice computational efficiency. In this paper, we develop a simple yet practical framework to efficiently craft targeted transfer-based adversarial examples. Specifically, we propose a conditional generative attacking model, which can generate the adversarial examples targeted at different classes by simply altering the class embedding and share a single backbone. Extensive experiments demonstrate that our method improves the success rates of targeted black-box attacks by a significant margin over the existing methods -- it reaches an average success rate of 29.6\% against six diverse models based only on one substitute white-box model in the standard testing of NeurIPS 2017 competition, which outperforms the state-of-the-art gradient-based attack methods (with an average success rate of $<$2\%) by a large margin. Moreover, the proposed method is also more efficient beyond an order of magnitude than gradient-based methods

Methyl 1-(2,6-difluoro­benz­yl)-1H-1,2,3-triazole-4-carboxyl­ate

In the title compound, C11H9F2N3O2, the triazole ring is planar, with an r.m.s. deviation of 0.0048 Å, and makes a dihedral angle of 77.3 (1)° with the benzene ring. In the crystal, weak inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link the mol­ecules into chains along the b axis