A modified multicomponent Biginelli condensation with Meldrum's acid affords a straightforward access to 5,6-dihydropyrimidin-4-ones through a domino Knoevenagel-aza-Michael-Cyclocondensation (KaMC) reaction.
Synthesis of 2- (and 6-) -dithian-2-yluracil nucleosides and their conversion into nucleoside derivatives
作者:A. Rosenthal、Robert H. Dodd
DOI:10.1016/s0008-6215(00)83658-7
日期:1980.1
)pyrimidinone ( 3 ), O 2 ,2′-anhydro-5,6-di-hydro-6-( S )-(1,3-dithian-2-yl)-5′- O -trityluridine ( 4 ), and 2-(1,4-dihydroxybutyl)-1,3-dithiane ( 5 ) in yields of 15, 30, and 10% respectively. The structure of 3 was proved by its hydrolysis in acid to give 2-(1,3-dithian-2-yl)-4-pyrimidinone ( 6 ) and arabinose, and by desulfurization with Raneynickel to yield the known 2-methyl-1-(5- O -trityl-β- D -
Linear free energy–steric strain energy relationships for the gem-di-methyl effect. Acid-catalysed ring closure of methyl-substituted 3-ureidopropionic acids
作者:Iva B. Blagoeva、Bogdan J. Kurtev、Ivan G. Pojarlieff
DOI:10.1039/p29790001115
日期:——
statistical criteria. Linearrelationships were obtained for the free energies in the reaction series for rates and equilibria exhibiting the gem-dimethyl effect with stericstrainenergies estimated from enthalpies of formation of homomorphic hydrocarbons. These estimates were obtained by means of Istomin and Palm's procedure and are of two kinds, the P values measuring the total strainenergy and ΔP values
Kinetic Studies on Dehydrogenation Reaction of 5,6-Dihydro-2,4(1<i>H</i>,3<i>H</i>)-pyrimidinediones in Aqueous Solution Induced by Argon Arc Plasma or Hydrogen–Oxygen Flame
5,6-Dihydro-2,4(1H,3H)-pyrimidinediones underwent dehydrogenation at the 5- and 6-position producing 2,4(1H,3H)-pyrimidinediones in aqueous solution induced by argon arc plasma or flames. From consideration based on the kinetic study of this reaction, it was found that abstraction of a hydrogen atom took place preferentially at the 6-position of the dihydropyrimidinediones.
Compositions and method for activating oxygen utilizing N-acylated
申请人:Henkel Kommanditgesellschaft auf Aktien
公开号:US04110242A1
公开(公告)日:1978-08-29
The method of activating aqueous solutions of percompounds utilizing N-acylated uracils and benzouracils as activators; solid activated compositions comprising solid percompounds and N-acylated uracils and benzouracils as activators; and novel diacylated uracils and benzouracils.