Abstract: The present invention provides a maleate, phosphate, sulfate, hydrochloride of a cyclohexane derivative, N?-[trans-4-[2-[7-(benzo[b]thiophene)-7-piperazinyl]ethyl]cyclohexyl]-N,N-dimethylurea, as shown in Formula I and crystal forms thereof. The crystal forms have low hygroscopicity and good stability and are convenient for long-term storage and transportation; or the crystal forms have a long half-life in vivo, high bioavailability and small individual difference, and thus have obvious clinical application advantages.

Abstract: The present invention provides a maleate, phosphate, sulfate, hydrochloride of a cyclohexane derivative, N?-[trans-4-[2-[7-(benzo[b]thiophene)-7-piperazinyl]ethyl]cyclohexyl]-N,N-dimethylurea, as shown in Formula I and crystal forms thereof. The crystal forms have low hygroscopicity and good stability and are convenient for long-term storage and transportation; or the crystal forms have a long half-life in vivo, high bioavailability and small individual difference, and thus have obvious clinical application advantages.

Abstract: Crystal forms I and II of tasimelteon. Crystal form I: an X-ray powder diffraction spectrum using CuK? radiation and represented by a 2? angle has diffraction peaks at least at 7.2°±0.2°, 7.9°±0.2°, 10.6°±0.2°, 14.4°±0.2°, 15.9°±0.2°, 17.3°±0.2°, 21.0°±0.2°, 23.2°±0.2°, and 24.4°±0.2°. Crystal form II: an X-ray powder diffraction spectrum using CuK? radiation and represented by a 2? angle has diffraction peaks at least at 6.8°±0.2°, 12.1°±0.2°, 12.5°±0.2°, 13.1°±0.2°, 13.6°±0.2°, 13.8°±0.2°, 15.8°±0.2°, 17.0°±0.2°, 18.4°±0.2°, 20.8°±0.2°, 24.2°±0.2°, and 24.4°±0.2°. Crystal forms I and II of tasimelteon have advantages of excellent physicochemical property, good stability and solubility, and simple operation for preparation.

Abstract: A cyclohexane derivative as shown by formula IB or a stereoisomer or a salt thereof, has a high affinity for D3 receptors and 5-hydroxytryptamine, has a lower affinity for D2 receptors, shows a high selectivity for D3/D2 receptors, and can be used as a therapeutic drug against neuropsychiatric diseases. wherein; X is N or CH; R is R is optionally substituted with one or more substituents selected from the group consisting of F, Cl, Br, I and C1-C6 alkyl; and the C1-C6 alkyl is optionally substituted with one or more substituents selected from the group consisting of F, Cl, Br, and I.

Abstract: Crystal forms I and II of tasimelteon. Crystal form I: an X-ray powder diffraction spectrum using CuK? radiation and represented by a 2? angle has diffraction peaks at least at 7.2°±0.2°, 7.9°±0.2°, 10.6°±0.2°, 14.4°±0.2°, 15.9°±0.2°, 17.3°±0.2°, 21.0°±0.2°, 23.2°±0.2°, and 24.4°±0.2°. Crystal form II: an X-ray powder diffraction spectrum using CuK? radiation and represented by a 2? angle has diffraction peaks at least at 6.8°±0.2°, 12.1°±0.2°, 12.5°±0.2°, 13.1°±0.2°, 13.6°±0.2°, 13.8°±0.2°, 15.8°±0.2°, 17.0°±0.2°, 18.4°±0.2°, 20.8°±0.2°, 24.2°±0.2°, and 24.4°±0.2°. Crystal forms I and II of tasimelteon have advantages of excellent physicochemical property, good stability and solubility, and simple operation for preparation.