Synthesis of 5-Alkyl-1,3-bis[2-hydroxy-3-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-3-yl)propyl]-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-diones

6-Methyluracil sodium salt reacts with 1,3-bis(3-chloro-2-hydroxypropyl)-6-methyluracils in DMF, yielding products of alkylation at the nitrogen atom in position 3 of the uracil ring.     

1,3-双[3-(1-甲氧基-2-羟基丙氧基)丙基]封端聚硅氧烷的合成

以1,3-双[3-(1-甲氧基-2-羟基丙氧基)丙基]四甲基二硅氧烷和八甲基环四硅氧烷(D4)为原料,通过阳离子催化开环聚合制备了1,3-双(3-(1-甲氧基-2-羟基丙氧基)丙基)封端聚硅氧烷,研究了反应温度,反应时间,催化剂种类及加入量对于聚合反应的影响,结果表明,最佳反应条件为:反应温度65℃,反应时间24h,浓硫酸作为催化剂加入量为反应物质量的0.3%,此时反应拥有最高的转化率。通过红外光谱与核磁共振光谱对产物进行了表征。     

Synthesis,Structure, and Conformational Analysis of N-(2,4-Dichlorophenyl)-2-[6-methyl-2,4-dioxo-3-(thietan-3-yl)-1,2,3,4-tetrahydropyrimidine-1-yl]acetamide

Russian Journal of General Chemistry - The reaction of 6-methyluracil with 2-chloromethyltiiran affords 6-methyl-3-(thietan-3-yl)uracil. Its subsequent reaction with...     

Synthesis of 1,3-Bis[2-hydroxy-3-(3-methyl-5-oxo-2,5-dihydro-1-pyrazolyl)propyl)uracils

A reaction was studied of newly synthesized 1,3-bis(2-hydroxy-3-chloropropyl)uracil and 1,3-bis(2-hydroxy-3-chloropropyl)-6-methyluracil with hydrazine hydrate followed by treating the compounds formed with ethyl acetoacetate. The hydrazones obtained cyclized into pyrazolones in the presence of sodium methylate.     

Synthesis of 5-acyl-6-[2-hydroxy-3-(amino)propylamino]-1,3-dialkyl-1H-pyrimidine-2,4-diones

A stepwise synthetic approach involving substitution of 6-chloro-1,3-dialkyluracils (5 and 6) with 3-(tert-amino)-2-hydroxypropylamines and subsequent acylation at C5 of uracil has been used to synthesize pyrimidinediones 27-33 in 61-89% overall yield. The conformational aspects of the new molecules based upon NMR data have been discussed.     

New organic nitrates. II. Synthesis of 2H-pyrido[2,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazin-4(3H)-ones, 2H-thieno[2,3-e]-1,3-oxazin-4(3H)-ones and 2H-thieno[3,4-e]-1,3-oxazin-2,4(3H)-diones

The preparation and the physico-chemical characterization of 2H-pyrido[2,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazin-4(3H)-ones, 2H-thieno[2,3-e]-1,3-oxazin-4(3H)-ones and 2H-thieno[3,4-e]-1,3-oxazine-2,4(3H)-diones are reported.     

Synthesis, characterization, crystal and molecular structure analysis of N-(2,4-dimethylphenyl)-6-methyl-4-(3-nitrophenyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxamide

A novel dihydropyrimidine (DHPM) derivative bearing a carbamoyl moiety was synthesized by an efficient three-component Biginelli reaction and was characterized spectroscopically and finally confirmed by X-ray diffraction studies. The title compound C₂₀H₂₀N₄O₄ crystallizes in the monoclinic space group P2₁/c with cell parameters a=12.8970(12) Å, b=13.6210(11) Å, c=11.8420(13) Å, β=115.860(3)°, Z=4 and V=1872.0(3) Å³. The conformation of the dihydropyrimidine ring is unusual; it is planar instead of the usual boat-like conformation. The 3-nitrophenyl ring is orthogonal to the 3,4-DHPM ring. The carbonyl group is in an anti-clinal conformation.     

1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯的合成

在冰浴条件下, 2-甲基噻吩(1)与液溴反应生成3,5-二溴-2-甲基噻吩(2); 在－78 ℃条件下, 硼酸三丁酯加入2, 得到2-甲基-3-溴-5-硼酸基噻吩(3); 3,4-二氟溴苯与3反应得到2-甲基-3-溴-5-(3,4-二氟苯基)噻吩(4); 在－78 ℃下全氟环戊烯与4反应, 得到一种新的二芳基乙烯类光致变色化合物1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯(DT-1). 用IR, NMR, MS和元素分析确定了化合物DT-1的结构, 并对该化合物的光致变色特性进行了初步研究.     

Synthesis of 2-[3-Aryl-3-(5-phenylisoxazol-3-yl)propyl] Derivatives of 5,5-Dimethylcyclohexane- and Cyclopenthane-1,3-diones Proceeding from 2-(4-Nitro-3-arylbutyl) Precursors

Regiospecific reduction of carbonyl group of acyl chain in the previously described 4-nitro-3-arylbutanoyl derivatives of dimedone and cyclopentane-1,3-dione was performed. On the basis of nitromethyl group of the enol derivatives of the reduction products obtained from the mentioned compounds nitrile oxide intermediates were prepared, which in situ reacted with phenylacetylene to form the corresponding isoxazole derivatives.     

Synthesis of 6-arylspiro[tetrahydropyran-3,1′-cyclobutane]-2,4-diones

Methyl 1-(2-bromo-2-methyl-1-oxopropyl)-, 1-(1-bromocyclopentylcarbonyl)-, and 1-(1-bromocyclohexylcarbonyl) cyclobutanecarboxylates reacted with zinc and aromatic aldehydes to give, respectively, 7-aryl-2,2-dimethyl-6-oxaspiro[3.5]nonane-5,9-diones, 11-aryl-12-oxadispiro[3.1.4.3]tridecane-5,13-diones, and 12-aryl-13-oxadispiro[3.1.5.3]tetradecane-5,14-diones.     

Synthesis of 1,3-Bis[(3-aryl)-S-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes

1,3-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]benzenes 2 were synthesized in high yields by the reaction of 3-aryl 4-amino-5-mercapto-1,2,4-triazole 1 with m-phthalic acid.     

Synthesis of 1,3-dialkylpyrazolo [1,5-a]-1,3,5-triazine-2,4-diones isomers of 1,3-dialkylxanthines

The synthesis of a new series of alkylxanthine analogs containing a bridgehead nitrogen atom is reported. 1,3-Dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones, were prepared by the treatment of 3-methylpyrazolo[1,5-a]-1,3,5-triazine-2,4-dione (3) with the corresponding alkyl iodide. Similarly, the reaction of 3-methyl-7-phenylpyrazolo[1,5-a]-1,3,5-dialkyl-7-phenylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones. The starting materials, 3 and 17 , were prepared via the reaction of an appropriate 3-aminopyrazole with ethoxycarbonyl isothiocyanate. Several 8-bromo derivatives were prepared by direct bromination of the 1,3-dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones.     

Synthesis of 3-(aminooxoethyl)-6-methyl-1-(thiethan-3-yl)-pyrimidine-2,4-(1H,3H)-diones

A new approach to prepare 2-chloroacetamides has been developed, based on the reaction of chloroacetyl chloride with excess of secondary amines. Alkylation of 6-methyl-1-(thiethan-3-yl)pyrimidine-2,4(1H,3H)-dione with the synthesized 2-chloroacetamides in the presence of potassium carbonate has afforded N ³-acetamido-substituted 6-methyl-1-(thiethan-3-yl)pyrimidine-2,4(1H,3H)-diones.     

Convenient Synthesis of 3-(1-Carboxyalkyl)pyrido[2,3-d]pyrimidine-2,4-diones

A cheap and safe synthetic route to obtain 3-(1-carboxyalkyl)pyrido[2,3-d]pyrimidinediones (carboxyalkyl = -CHRCO₂H; R = H; CH₂; CH₂Ph; Ph; CH₂ (C₃H₃N₂); (CH₂)₂CO₂H; CH₂CO₂H) starting from 2,3-pyridinedicarboxylic acid is described. A process scheme consistent with empirical observations is proposed.     

Ring transformation of 6-methyl-3,4-dihydro-2H-1,3-oxazine-2,4-diones

Ring transformation of 6-methyl-3,4-dihydro-2H-1,3-oxazine-2,4-dione (Ia) and its N-sub-stituted derivatives, such as 3-methyl (Ib), 3-ethyl (Ic), and 3-benzyl (Id) derivatives is described. Reaction of Ia with hydrazine hydrate gave 1-amino-6-methyluracil (II), while Id reacted with hydrazine hydrate to give 3-hydroxy-5-methylpyrazole (III). Reaction of Ia,b,d with ethyl acetoacetate in ethanol in the presence of sodium ethoxide afforded ethyl 3-acetyl-6-hydroxy-4-methyl-2(1H) pyridone-5-carboxylate derivatives (IVa,b,d). On the other hand, reaction of Ib,c,d with ethyl acetoacetate in tetrahydrofuran in the presence of sodium hydride did not give IV, but gave 3-acetyl-1-alkyl-5-(N-alkylcarbamoyl)-6-hydroxy4-methyl-2(1H) pyridone (VIb,c,d). Mechanisms for the formation of compounds IV and VI are discussed.     

Synthesis of 1-[3-methyl-2(3H)-benzazolon-5- or 6-yl]-4-{4-[cis-2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl-methyl)-1,3-dioxolan-4-yl]methyleneoxyphenyl}piperazines

Reactions of 3-methyl-6-[4-(4-hydroxyphenyl)-1-piperazinyl]-2(3H)-benzoxazolone, 3-methyl-6-[4-(4-hydroxy-phenyl)-1-piperazinyl]-2(3H)-benzothiazolone and 1,3-dimethyl-5-[4-(4-hydroxyphenyl)-1-piperazinyl]-2(3H)-benzimidazolone with cis-{[2-(2,4-dichlorophenyl) -2-(1H-imidazol-1-ylmethyl)]-1,3-dioxolan-4-yl}methyl meth-anesulfonate in the presence of sodium hydride furnish the title compounds.