Abstract: Crystals of (((R)-12?-((S)-7,8-difluoro-6,11-dihydrodibenzo[b,e]thiepin-11-yl)-6?,8?-dioxo-6?,8?,12?,12a?-tetrahydro-1?H,4?H-spiro[cyclopropane-1,3?-[1,4]oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin]-7?-yl)oxy)methyl methyl carbonate, i.e. compound of formula (1) or a solvate thereof and a preparation method therefor. The crystals include crystal form A, crystal form B, crystal form C, crystal form D, crystal form E, crystal form F, and single crystal. The crystal of the compound of formula (1) or a solvate thereof can be individually used for clinical treatment or in combination with other anti-influenza drugs such as neuraminidase inhibitors, nucleoside drugs, or PB2 inhibitors, are capable of clinically curing influenza patients quickly, and have very good activity and good bioavailability compared to existing pyridone derivatives. In addition, the stability, hygroscopicity, and storability of the crystals meet the requirements for pharmaceutical use.

Abstract: Disclosed in the present disclosure are a heterocyclic derivative represented by formula (I), or a stereoisomer, a pharmaceutically acceptable salt thereof. The heterocyclic derivative or the stereoisomer thereof has high HCMV inhibiting activity, which is increased in potency by 8-40 folds compared with letermovir, and clinically it may provide better protection for patients suffering from HCMV infection after allogeneic hematopoietic stem cell transplantation, kidney transplantation, and lung transplantation.

Abstract: Provided are crystals of (((R)-12?-((S)-7,8-difluoro-6,11-dihydrodibenzo[b,e]thiepin-11-yl)-6?,8?-dioxo-6?,8?,12?,12a?-tetrahydro-1?H,4?H-spiro[cyclopropane-1,3?-[1,4]oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin]-7?-yl)oxy)methyl methyl carbonate, i.e. compound of Formula (1) or a solvate thereof and a preparation method therefor, the crystals comprising crystal form A, crystal form B, crystal form C, crystal form D, crystal form E, crystal form F, and single crystal. The crystal of the compound of Formula (1) or a solvate thereof can be individually used for clinical treatment or in combination with other anti-influenza drugs such as neuraminidase inhibitors, nucleoside drugs, or PB2 inhibitors, being capable of clinically curing influenza patients quickly, and having very good activity and good bioavailability compared to existing pyridone derivatives. In addition, the stability, hygroscopicity, and storability of the crystals meet the requirements for pharmaceutical use.