Convenient and Versatile Synthetic Methods for Furazano[3,4-d]pyrimidines
作者:Magoichi Sako、Souichi Oda、Kosaku Hirota、George P. Beardsley
DOI:10.1055/s-1997-1349
日期:1997.11
Treatment of the readily available 6-amino-5-nitrosopyrimidines with a slight excess of iodobenzene diacetate or N-iodosuccinimide in anhydrous DMF containing three equivalents of lithium hydride at ambient temperature resulted in the smooth and versatile formation of the corresponding furazano[3,4-d]pyrimidines, which are useful intermediates for the preparation of biologically interesting fused pyrimidines.
Ring closure reactions of β-nitroso-, β-acyl-, and β-thiocarbamoyl-α,β-unsaturated sulfilimines. Synthesis of [1,2,5]oxadiazolo[3,4-d]-, isoxazolo[3,4-d]-, and isothiazolo[3,4-d]pyrimidine derivatives from uracils
作者:Nobuaki Matsumoto、Masahiko Takahashi
DOI:10.1016/s0040-4020(02)01302-9
日期:2002.12
acils were treated with S,S-diphenylsulfilimine to give N-(1,3-dialkyluracil-6-yl)-S,S-diphenylsulfilimines. The uracilylsulfilimines were nitrosated, acylated, or thiocarbamoylated to give N-(5-nitroso-, 5-acyl-, or 5-thiocarbamoyluracil-6-yl)sulfilimines, respectively. These conjugated sulfilimines were cyclized by thermolysis or photolysis to [1,2,5]oxadiazolo[3,4-d], isoxazolo[3,4-d], or isothiazolo[3
将1,3-二烷基-6-氯尿嘧啶用S,S-二苯基硫亚胺处理,得到N-(1,3-二烷基尿嘧啶-6-基)-S,S-二苯基硫亚胺。尿嘧啶亚氨基嘧啶被亚硝化,酰化或硫代氨基甲酰化,分别得到N-(5-亚硝基-,5-酰基-或5-硫代氨基甲酰基尿嘧啶-6-基)亚磺酰亚胺。通过热解或光解将这些共轭的亚硫亚胺环化为[1,2,5]恶二唑并[3,4- d ],异恶唑并[3,4- d ]或异噻唑并[3,4- d ]嘧啶衍生物。
Mechanistic aspects of the oxidation of 1,3-disubstituted 6-amino-5-nitrosouracils with lead tetraacetate: the formation of pyrimido[5,4-g]pteridinetetrone 10-oxides
作者:Magoichi Sako、Seiji Ohara、Kosaku Hirota、Keuji Kano、Yoshifumi Maki、Edward C. Taylor
DOI:10.1021/jo00022a017
日期:1991.10
Lead tetraacetate oxidation of 1,3-disubstituted 6-amino-5-nitrosouracils 1 in glacial acetic acid results in the formation of 1,3,6,8-tetrasubstituted pyrimido[5,4-g]pteridine-2,4,5,7(1H,3H,6H,8H)-tetrone 10-oxides 2. ESR studies and a number of chemical observations suggest a novel reaction sequence involving oxidative dimerization of 1 followed by intramolecular cyclization, oxidation, and homolytic elimination of nitrous oxide.