Stable salts and crystalline forms of small molecule compounds having selective CB2 receptor agonistic activity

The present invention relates to novel salts and crystalline forms of 2-[3-({1-[2-(dimethylamino) ethyl]-2-(2, 2-dimethylpropyl)-1H-1, 3-benzodiazol-5-yl} sulfonyl) azetidin-1-yl] ethyl-1-ol, in particular to novel salts and crystalline forms of 2-[3-({1-[2-(dimethylamino) ethyl]-2-(2, 2-dimethylpropyl)-1H-1, 3-benzodiazol-5-yl} sulfonyl) azetidin-1-yl] ethyl-1-ol. The invention discloses 2-[3-({1-[2-(dimethylamino) ethyl]-2-(2, 2-dimethylpropyl)-1H-1, 3-benzodiazole-5-yl} sulfonyl) azetidine-1-yl] ethyl-1-ol which is called a compound A for short, and the compound A is a selective CB2 receptor agonist. The invention provides a salt of a compound A, a crystal form of the salt, a method for preparing the salt, a pharmaceutical composition of the salt and application of the salt. The salt of the compound A according to the present invention exhibits good pharmaceutical preparation characteristics such as high water solubility, good crystallinity, high melting point, good chemical and physical stability, or diff