3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Th...3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.展开更多
Four pyridazinone gluosodes 4 were synthesized by Koenig′s Knorr reaction of 6 (4 halophenyl) 3( 2H ) pyridazinone silver salt 2 with bromoacetylglucose 3.Treatment of 4 with dry ammonia at 0～-5℃ effected a removal...Four pyridazinone gluosodes 4 were synthesized by Koenig′s Knorr reaction of 6 (4 halophenyl) 3( 2H ) pyridazinone silver salt 2 with bromoacetylglucose 3.Treatment of 4 with dry ammonia at 0～-5℃ effected a removal of the acetyl protecting groups to yield compounds 5.When the substituent on the benaene ring was F or Cl ,O glucoside was synthesized principally.However,when the substituent was Br or I ,N glucoside was mainly obtained.Their structures were confirmed by 1H NMR,IR and elemental analysis.展开更多
Benzoxazinone usually exists in many kinds of plants.It is applied in prepharmacy synthesis,and bioactivity studies,and has been prepared from O-aminophenol and chrol-with alkine and solvent by refluxing for a long ti...Benzoxazinone usually exists in many kinds of plants.It is applied in prepharmacy synthesis,and bioactivity studies,and has been prepared from O-aminophenol and chrol-with alkine and solvent by refluxing for a long time.In this work,2,2’-diphenyl-1,4-benzoxazin-3(4H)-one was solvent-free synthesized under microwave irradiation.The configuration and conformation of the product were determined by 1H NMR,IR,MS,elementary analysis and X-ray crystal analysis.The results of X-ray crystal analysis show that the compound crystallizes in a triclinic system,space group %P%1,cell parameter %a%=0.840 7(1)nm,%b%=0.845 1(1)nm,%c%=2.254 1(3)nm,%α%=96.111(3)°,%β%=97.196(3)°,%γ%=90.229(3)°,%V%= 1^579 6(4)nm3,%Z%=4,%D%c =1.267 Mg/m3,%F%(000)= 632.0,%μ%= 0.08 mm-1.In the compound,oxazinone ring is shown chair conformation,two benzene rings is placed in two sides of oxazinone ring distortedly.In crystal state,a centrosymmetric dimmer is formed %via% hydrogen bonds generated from amides of two near molecules.The benzene rings in a same chemical environment are paralleled by a distance of 0.260 9 nm.It displays aromatic π-π stacking interactions.展开更多
文摘3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.
文摘Four pyridazinone gluosodes 4 were synthesized by Koenig′s Knorr reaction of 6 (4 halophenyl) 3( 2H ) pyridazinone silver salt 2 with bromoacetylglucose 3.Treatment of 4 with dry ammonia at 0～-5℃ effected a removal of the acetyl protecting groups to yield compounds 5.When the substituent on the benaene ring was F or Cl ,O glucoside was synthesized principally.However,when the substituent was Br or I ,N glucoside was mainly obtained.Their structures were confirmed by 1H NMR,IR and elemental analysis.
文摘Benzoxazinone usually exists in many kinds of plants.It is applied in prepharmacy synthesis,and bioactivity studies,and has been prepared from O-aminophenol and chrol-with alkine and solvent by refluxing for a long time.In this work,2,2’-diphenyl-1,4-benzoxazin-3(4H)-one was solvent-free synthesized under microwave irradiation.The configuration and conformation of the product were determined by 1H NMR,IR,MS,elementary analysis and X-ray crystal analysis.The results of X-ray crystal analysis show that the compound crystallizes in a triclinic system,space group %P%1,cell parameter %a%=0.840 7(1)nm,%b%=0.845 1(1)nm,%c%=2.254 1(3)nm,%α%=96.111(3)°,%β%=97.196(3)°,%γ%=90.229(3)°,%V%= 1^579 6(4)nm3,%Z%=4,%D%c =1.267 Mg/m3,%F%(000)= 632.0,%μ%= 0.08 mm-1.In the compound,oxazinone ring is shown chair conformation,two benzene rings is placed in two sides of oxazinone ring distortedly.In crystal state,a centrosymmetric dimmer is formed %via% hydrogen bonds generated from amides of two near molecules.The benzene rings in a same chemical environment are paralleled by a distance of 0.260 9 nm.It displays aromatic π-π stacking interactions.
