The reaction of 5 methyl 7 phenyl 4,7 dihydro 1,2,4 triazolo[1,5 a]pyrimidine with α,β unsaturated carbonyl compounds in MeOH in the presence of MeONa affords partially hydrogenated aryl substituted [1,2,4]triazolo[5,1 b]quinazolines. Hydrolysis, oxidation, re duction, and alkylation of 5,6,8 triphenyl 5,6,7,10 tetrahydro[1,2,4]triazolo[5,1 b]quinazoline were studied. The structure of one oxidation product, viz., 7 hydroxy 5,6,8 triphenyl 6,7 dihydro[1,2,4]triazolo[5,1 b]quinazoline, was established by X ray diffraction.Partially hydrogenated quinazoline systems have at tracted interest from both fundamental and applied points of view. Most structures of this type belong to so called drug like molecules or are present in natural biologically active compounds, for example, in alkaloids. 1 Adenosine uptake inhibitors (potent vasodilators and antiaggre gants) 2,3 and carbocyclic purine analogs exhibiting anti metabolic activity were found in the azoloquinazoline series. 4 At the same time, these compounds are conve nient models for elucidating some questions of theoreti cal organic chemistry, in particular, the characteristic fea tures of the three dimensional and electronic structures of partially hydrogenated nitrogen containing hetero cycles, their stability, and reactivity.There are two main procedures for the formation of azoloquinazoline systems. The most widely used proce dure is based on the construction of the pyrimidine ring in reactions of α aminoazole derivatives with carbonyl 1,3 bielectrophiles containing a partially or completely hy drogenated carbocycle. 5-12 A nontrivial procedure has been developed earlier for the assembly of 2 methyl 5,10 diphenyl 5,10 dihydro[1,2,4]triazolo[5,1 b]quinazolines based on the cascade reaction giving rise to both the triazole and quinazoline fragments. 13 However, the pyri midine ring closure in this process is also preceded by the formation of the aminotriazole fragment. An alternative approach to the desired compounds is associated with the formation of the five membered azole ring based on the already present quinazoline moiety, but this method is synthetically more limited. 14 Recently, 15 we have described yet another procedure for the synthesis of [1,2,4]triazolo[5,1 b]quinazolines, which differs from the above mentioned methods in that the carbocycle closure occurs on the basis of the already present partially hydro genated 5 methyl 7 phenyl 1,2,4 triazolo[1,5 a]pyrimi dine system with the involvement of 1,3 diaryl 2 propen 1 ones in an alcoholic medium in the presence of MeONa.The aim of the present study was to extend the range of carbonyl 1,3 bielectrophiles, which react with 5 me thyl 7 phenyl 4,7 dihydro 1,2,4 triazolo[1,5 a]pyrimi dine (1) to give partially hydrogenated [1,2,4]triazo lo[5,1 b]quinazoline systems (Scheme 1), and to study the chemical behavior of the latter in hydrolysis, oxida tion, reduction, and alkylation reactions.It was found that refluxing of equimolar amounts of carbonyl 1,3 bielectrophiles 2a,b, 4, 6, 9, and 11 with dihydrotriazolo...
Reactions of 4,7-Dihydro-1,2,4-triazolo [1,5-a]pyrimidines with α,β-Unsaturated Carbonyl Compounds Victoria V. Lipson[a], Irina V. Ignatenko[a], Sergey M. Desenko[b], Svetlana V. Shishkina[b], OlegThe reaction of 5,7-diphenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (1) with α,β-unsaturated carbonyl compounds 2a-f led to the formation of the alkylated heterocycles 3a-f (Figure 1). However, the reaction of 5-methyl-7-phenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (5) with 2a-c yielded under the same conditions the triazolo[5,1-b]quinazolines 6a-c (Figure 3). In this case, the alkylation is followed by a cyclocondensation. The structure elucidation of the products is based on ir, ms, 1 H and 13 C nmr measurements and on an X-ray diffraction study.
A B S T R A C TThe purpose of the article is to consider the prospects of Ukraine concerning attraction of foreign investments into production of organic products. Formal-legal, materialist dialectics and comparative-legal methods are used. The attention is focused on the subjects of legal relations concerning organic production, in particular, on joint ventures with attraction of foreign capital, the stages of certification regarding the production of organic products. The temporary restrictions on the possession of agricultural land in some EU countries and in Ukraine have been analyzed. A comparative analysis of land lease institutions and the right to use another's land for agricultural needs (emphyteusis) has been carried out.
The article deals with the rights to agricultural land under the conditions of the moratorium on the alienation of agricultural land in Ukraine. Currently land lease is the most widespread land-use right in Ukraine. The purpose of the article is to investigate the features and prospects of the functioning of the land market in Ukraine and to increase investor interest in it. The dialectical method made it possible to consider the development of land-use rights in Ukraine, to formulate proposals for improving existing legislation. The method of comparative legal analysis made it possible to compare the system of relations of land ownership and lease in Ukraine and other countries of the world. Much attention has been paid to the abolition of the moratorium on the purchase of agricultural land in Ukraine, which will lead to a gradual increase in the share of entrepreneurial activity on owned land with an optimal ratio of land lease. Based on the features of agricultural land lease, the following positive points are highlighted: 1) the availability of long-term lease guarantees the tenant’s stability in land use and promotes better planning and investment attractiveness; 2) the ability to set a fixed size of land rent without taking into account the normative monetary valuation; 3) rents for agricultural land in Ukraine continue to be much lower than in other countries.
In modern economic conditions, organic production is gaining global significance, partly addressing food security and contributing to the well-being of the population. Ukraine is in the top-20 of world leaders in the organic movement. In this regard, the prospects for the development of organic farming are considered. The current state of regulatory support for organic production in Ukraine has been analyzed. It is proposed to approve the procedure for certification of organic production, the procedure and requirements for labeling of organic products, as well as requirements for material and technical base and other infrastructure necessary to perform functions of certification of organic production and circulation of organic products. The necessity of approving the criteria for determining the suitability of agricultural lands for use in the process of organic production is substantiated.
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