Synthesis of Substituted Heterocyclic Thiourea Compounds

Heterocyclic thioureas having multiple substitutions were prepared in two steps with overall yields of 60–80%. Condensation of a substituted heterocyclic amine with thiocarbonyldiimidazole, followed by treatment with a disubstituted phenylethylamine in dimethyl formamide (DMF), yielded the desired heterocyclic thioureas as crystalline solids.     

Synthesis of Isopropylidene Malonate Substituted Heterocyclic Ketene N-Acetals

Isopropylidene malonate substituted heterocyclic ketene N, N-acetals 2a-g, N, S-acetals 2h, i and N, O-acetals 2j-1 were synthesized from ketene S, S-acetal 1.     

The Synthesis of Substituted 2-Aminophenyl Heterocyclic Ketones

The synthesis of substituted 2-aminophenyl heterocyclic ketones, key intermediates to the preparation of 1,4-benzodiazepines has been achieved in one step and in good, yield from the corresponding anthranilic acid, by treatment with heterocyclic lithium reagents and chlorotrimethylsilane.     

Efficient Synthesis of Substituted Indene Derivatives

An efficient protocol for the synthesis of new functionalized indenes 3 was successfully realized. Thus the coupling reaction of allyl acetate 2 with Grignard reagents in the presence of a catalytic amount of LiCuBr₂ at low temperature afforded pure ethyl 1-alkyl-1H-indenes-2-carboxylate 3 in good yields.     

An Efficient Synthesis for Some New Heterocyclic Compound‐fused Oxindole Derivatives

An efficient and rapid procedure for the synthesis of novel oxindole derivatives is described. The process employs a condensation reaction of 3‐(bis(methyl thio)methylene)indolin‐2‐one and dinucleophiles such as 1,2‐phenylene diamine, propylene diamine, 2‐aminoethanol, ethylene‐1,2‐dithiol, 2‐mercaptoethanol, (1S,2S)‐cyclohexane‐1,2‐diamine, 2‐aminoethanthiol, 2,3‐diaminomaleonitrile, 2‐aminobenzenethiol, (3,4‐diaminophenyl)(phenyl)methanone, and ethane‐1,2‐diole in the presence of triethylamine under solvent‐free conditions at 60°C.     

Synthesis and Reactions of Some Substituted Heterocyclic Systems as Anti-arrhythmic Agents

A series of substituted heterocyclic systems were prepared from N ¹-[4-(2-thienylmethylene)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Condensation of the thienylmethylene derivative with guanidine hydrochloride, urea, or thiourea afforded the aminopyrimidine, pyrimidinone, and thioxopyrimidine derivatives. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. Treating of the thienylmethylene derivative with phenylhydrazine or hydrazine hydrate in dioxane afforded N-phenylpyrazoline and a pyrazoline, which was reacted with acetyl chloride in dioxane affording the N-acetyl analogue. The thienylmethylene derivative was reacted with malononitrile or ethyl cyanoacetate in the presence of ammonium acetate to yield the corresponding cyanoaminopyridine and cyanopyrimidone derivatives. Also, it was reacted with hydroxylamine hydrochloride in pyridine to give the oxime derivative, which was cyclized with acetic anhydride. On the other hand, condensation of the thienylmethylene derivative with ethyl cyanoacetate in the presence of sodium ethoxide or cyanothioacetamide gave the cyanopyrane and pyridine thione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.     

Synthesis and Reactions of Some Substituted Heterocyclic Systems as Anti-arrhythmic Agents

Summary. A series of substituted heterocyclic systems were prepared from N ¹-[4-(2-thienylmethylene)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Condensation of the thienylmethylene derivative with guanidine hydrochloride, urea, or thiourea afforded the aminopyrimidine, pyrimidinone, and thioxopyrimidine derivatives. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. Treating of the thienylmethylene derivative with phenylhydrazine or hydrazine hydrate in dioxane afforded N-phenylpyrazoline and a pyrazoline, which was reacted with acetyl chloride in dioxane affording the N-acetyl analogue. The thienylmethylene derivative was reacted with malononitrile or ethyl cyanoacetate in the presence of ammonium acetate to yield the corresponding cyanoaminopyridine and cyanopyrimidone derivatives. Also, it was reacted with hydroxylamine hydrochloride in pyridine to give the oxime derivative, which was cyclized with acetic anhydride. On the other hand, condensation of the thienylmethylene derivative with ethyl cyanoacetate in the presence of sodium ethoxide or cyanothioacetamide gave the cyanopyrane and pyridine thione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.     

马蹄金素杂环衍生物的合成及抗乙肝病毒活性

以马蹄金素[N-(N-苯甲酰基-L-苯丙氨酰基)-O-乙酰基-L-苯丙氨醇,MTS]为先导化合物,设计并合成了16个杂环取代的马蹄金素衍生物,其结构经NMR,ESI-MS和元素分析确证.以HepG2 2.2.15细胞为乙肝病毒(HBV)载体,对合成的马蹄金素衍生物进行了抗HBV活性测试.实验结果表明,在测试浓度范围内,化合物5b(IC50=8.20μg/L,SI=10.26),5g(IC50=5.58μg/L,SI=22.78)和5i(IC50=5.07μg/L,SI=16.67)的抗HBV活性较强;在8μg/mL的浓度下,其抑制率分别为56.57%,67.06%和66.83%.     

Asymmetric Cycloaddition: An Efficient Synthesis of Enantiopure Isoxazolines Substituted with Carbohydrate Analogues

A simple and convenient method for the synthesis of heterocycles substituted with carbohydrate analogs is described. The chiral optically pure five‐membered glycoconjugates containing the isoxazoline unit were obtained by an aromatic nitrile oxides cycloaddition with 1‐phenyl‐1,2‐dihydro‐pyridazine‐3,6‐dionyl N‐glycoside derivatives.     

零价铜催化含氮杂环的N-芳基化合物的合成

由于氮的负性基团的亲核性低,使得在芳香卤代物的环上引入含氮基团的反应(或者说在含氮杂环化合物的亚氨基上进行 N-芳基化)不易进行,因而需要强烈的反应条件或加入催化剂促使反应的发生。曾有人用一价铜盐作为催化剂研究了芳香卤代物的亲核取代反应。本文用零价铜催化的方法,合成了 N-芳基含氮杂环化合物(3 a～h)。反应机理可能是芳香肉代物与铜首     

Efficient Synthesis of N‐Substituted 2,4‐Azepandione Ring System as an Active Intermediate for Heterocyclic Syntheses

An improved efficient synthesis for 2,4‐azepandiones ( 3 , 8 , and 14 ) could be achieved by a careful control of the reaction conditions to cyclize ethyl 4‐(N‐acetylarylamino) butanoate ( 1 , 7 , and 13 ), respectively. The ethyl 4‐arylamino butanoate ( 9 or 12 ) was prepared by stirring the ethyl 4‐bromobutanoate and substituted anilines at room temperature. Then, they were acetylated with acetyl chloride and triethylamine under the conditions that avoid the formation of 2‐pyrrolidinone derivatives 10 . Due to the rapid decomposition of the acetylated product ( 7 or 13 ) to its starting material ( 9 or 12 ), the reaction mixture is directly transferred without workup to the next cyclization step. The azepandione synthesis is favored by using a weak base at low temperature, where it is in a competition with the other modes of ring closure. The structures of the new compounds were supported by correct analytical and spectral data.     

Polystyrene-supported Benzyl Selenide: An Efficient Reagent for Highly Stereocontrolled Synthesis of Substituted Olefins

Solid-phase methodology has been rapidly and extensively applied to the preparation of small organic molecules recently1. It might be argued that selenoxide syn-elimination provided the principal impetus for the development of organoselenium chemistry. In addition, the required selenoxides are readily available from the oxidation of the corresponding selenides, which in turn can be prepared by the reaction of selenium-stabilized carbanions with various electrophilic substrates2. However, or…     

Efficient Route for the Synthesis of Highly Substituted Pyrroles

A mild and efficient synthesis of highly substituted pyrroles using the reaction of triphenylphosphine, α-diketone, ammonium acetate, and dialkyl acetylenedicarboxylates is described.     

6-氯吡啶-3-亚甲基取代杂环化合物的合成

以2-氯-5-氯甲基吡啶、苯基哌嗪、1-苯基-3-甲基-2-吡唑酮为原料,通过3条路线合成了6个新的6-氯吡啶-3-亚甲基取代杂环化合物,其结构经1H NMR,MS和元素分析表征.     

Efficient Synthesis of Chromone and Flavonoid Derivatives with Diverse Heterocyclic Units

Chromones and flavonoids are important bioactive compounds. We envisioned that new heterocyclic‐substituted chromones or flavonoids might act as new bioactive compounds. To obtain diverse molecules, we developed an efficient one‐pot synthesis by Michael aldol reaction of chromone and flavonoid derivatives bearing heterocyclic units. The 2,3‐heterocyclic‐substituted chromones were obtained in one step. Moreover, the use of substituted benzaldehydes and subsequent addition of heterocyclic aldehydes gave 3‐pyridyl‐substituted flavones. We also examined these one‐pot reactions in the solid phase. To introduce an additional point of diversity into the molecules, Suzuki–Miyaura coupling was performed. Furthermore, we identified the cytotoxicity of the synthesized compounds against cancer cells (PANC1 and HeLa cells). Several compounds were cytotoxic to these cancer cells.     

Efficient Domino Strategy for the Synthesis of Substituted Bipyrazole Derivatives

An efficient domino strategy for the synthesis of bipyrazole derivatives has been established successfully using Y(OTf)₃ as catalyst. This new reaction allows direct formation of highly functionalized bipyrazole derivatives with a wide diversity in substituents in a one‐pot manner. The present synthesis shows attractive characteristics, such as the use of water as reaction media, simple one‐pot operation, highly efficient catalyst, and mild reaction conditions.     

An Efficient,Multicomponent, One‐pot Synthesis of Tetra Substituted Pyrans in Water

A new and environmentally benign multi‐component synthesis of tetra substituted 4H‐pyran derivatives is developed via the one‐pot reaction of an aromatic aldehyde, malononitrile, and 1,3‐diketone in the presence of NaOH with water as the solvent at RT. The reaction is efficient and affords excellent yields of the products.     

Synthesis of Benzoyl Substituted Heterocyclic Ketene Aminals by Condensation of Benzoyl Ketene Mercaptals with Diamines

2-(Benzoylmethylene)imidazolidines 2 and 5,-hexahydropyrimidines 3 and 6, or -hexahydro-1H-1,3-diazepines 4 were synthesized by the reaction of benzoyl substituted ketene mercaptals 1 with diamines.