We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure...We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure of impurity B of Flurnazenil was confirmed by 1n N/V[R, 13C NMR and HRMS, and the overall yield was 29.3%. The finding will be helpful for optimizing the synthetic process and quality control of Flumazenil.展开更多
We have investigated the effects of B impurities on the structure and mechanical properties of NiA1 intermetallics by using a first-principles pseudopotential total-energy method, based on the density functional theor...We have investigated the effects of B impurities on the structure and mechanical properties of NiA1 intermetallics by using a first-principles pseudopotential total-energy method, based on the density functional theory with a generalized gradient approximation. We found that the impurity B atoms can either replace Ni atoms or Al atoms or both, depending on the surround- ing environment. We demonstrated that the presence of B will cause an increase in brittleness and a decrease in the ductility of NiAI for the Al-substitutional case, while causing an increase in the ductility of NiAl for the Ni-subtitutional case, based on the calculated elastic constants and the empirical criterions. This indicates that the effects of B impurities on the mechanical prop- erties of NiAl intermetallics are quite composition-dependent.展开更多
文摘We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure of impurity B of Flurnazenil was confirmed by 1n N/V[R, 13C NMR and HRMS, and the overall yield was 29.3%. The finding will be helpful for optimizing the synthetic process and quality control of Flumazenil.
基金supported by the Basic Research Project of High Education (Grant No. ZXH2009C004)the Foundation of CAUC (Grant No. 09QD06X)
文摘We have investigated the effects of B impurities on the structure and mechanical properties of NiA1 intermetallics by using a first-principles pseudopotential total-energy method, based on the density functional theory with a generalized gradient approximation. We found that the impurity B atoms can either replace Ni atoms or Al atoms or both, depending on the surround- ing environment. We demonstrated that the presence of B will cause an increase in brittleness and a decrease in the ductility of NiAI for the Al-substitutional case, while causing an increase in the ductility of NiAl for the Ni-subtitutional case, based on the calculated elastic constants and the empirical criterions. This indicates that the effects of B impurities on the mechanical prop- erties of NiAl intermetallics are quite composition-dependent.
