Pyrimidines. XIX. Pyrimido[4,5‐e]dihydro‐1,3‐oxazines and related compounds

Abstract

A number of 2‐substituted 4,5‐dihydroxy‐6‐(substituted aminomethyl)pyrimidines (VIII) were prepared from the corresponding 2‐substituted 4,5‐dihydroxypyrimidines (VII) by a new pyrimidine Mannich reaction. The structure of VIII was proved by an independent synthesis. Further study of this reaction led to the synthesis of a new class of compounds: the pyrimido[4,5‐e]dihydro‐1,3‐oxazines (VI).

Efficient synthesis of novel 4-benzoyl-7-thioxo-4,6,7,8-tetrahydro-2H- pyrimido[5,4-e][1,3]oxazine-2,5(3H)-diones via one-pot three-component reaction under thermal and microwave conditions

“…In addition, some uorescent dyes such as Nile blue and Nile red are based on the aromatic benzophenoxazine. Morever, these compounds are the core of many strategic and widely used drugs, which have received excellent feedback in medical and chemical research [30] such as; antihuman immunode ciency virus (HIV) A [31], anticancer B [32], antitumor C [33], as antibiotic D [34], DGAT1 inhibitor E [35], 2-amino-4-hydroxy-6phenylethyl-7H-pyrimido [4,5-b] [1,4]oxazine F [36], 2-amino-4-hydroxy-6-phenylpropyl-7H-pyrimido [4,5-b] [l,4]oxazine G [29], diacylglycerol acyltransferase H [35]. (Figure 1.…”

“…Several successful methods for the synthesis of pyrimido [5,4-e][1,3]oxazine have been reported by diverse procedures, such as; the intermolecular cyclization [31][32]37], metallic and non-metallic catalysts [26,38], the multi-component reaction [34,39,40], cycloaddition reaction [41][42][43], multi-steps reaction [23,25,[43][44][45][46], and Diels-Alder reaction [33].…”