Natural eutectic salts catalyzed one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones

The rapid, very simple and green one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones by condensation of the thioureas with chloroacetyl chloride and an aldehyde in natural deep eutectic solvent with good to excellent yields is described.     

A convenient synthesis of novel 5-arylidene-2-imino-4-thiazolidinones using base supported ionic liquid-like phase (SILLP) as efficient green catalyst

A facile and convenient protocol was developed for the synthesis of 5-arylidene-2-imino-4-thiazolidinones using solid basic catalyst immobilized onto supported ionic liquid-like phase (SILLP) in high yields (80?C95%). The X-ray analysis of the representative compound established the Z configuration of the product at the chiral axis.     

4-Thiazolidinones in heterocyclic synthesis: synthesis of novel enaminones, azolopyrimidines and 2-arylimino-5-arylidene-4-thiazolidinones

The 4-thiazolidinones 3a-d were used as a key intermediates for the synthesis of 2-arylimino-5-arylidene-4-thiazolidinones derivatives 7a–p via nucleophilic addition reactions with the arylidene malononitrile. Moreover the 4-thiazolidinones 3a and 3c condensed with the DMF-DMA to form the corresponding enamines 8 and 9 depending on the reaction conditions. Otherwise the 4-thiazolidinone 3b reacts regioselectively with DMF-DMA to afford the enaminones 10 and 11, respectively. The latter reacts with many heterocyclic amines affording polyfunctionally substituted fused pyrimidine derivatives 13-18. The enamine 8b was also reacted with the 3-amino-1,2,4-triazole to afford the acyclic product 19, which could not be further cyclized to the corresponding tricyclic system 20. Moreover the 4-thiazolidinone 3c reacted with the benzenediazonium chloride to afford the arylhydrazones 12. The X-ray single crystal technique was employed in this study for structure elucidation and Z/E potential isomerism configuration determination. The X-ray crystallographic analyses of eight products could be obtained, thus establishing with certainty the structures proposed in this work.     

A Facile Synthesis of 5-Arylidene-2-imino-4-thiazolidinones Under Microwave Irradiation

A series of 5-arylidene-2-imino-4-thiazolidinone derivatives were synthesized by the cross-aldol condensation of aromatic aldehydes with 2-imino-4-thiazolidinone in sodium acetate/acetic acid under microwave irradiation. The reactions were completed in 10 min with 63–91% yields, were environmental benign, and had easy workup.     

Solvent-free synthesis of 2-amino-4-arylthiazoles under microwave irradiation

2-Amino-4-arylthiazoles were prepared in a one-pot solvent-free procedure by reaction of p-substituted acetophenones with thiourea and iodine under microwave irradiation.     

在微波作用、无催化剂的条件下合成3-芳基亚甲基-1，3-二氢-2H-吲哚-2-酮类化合物

用DMF作溶剂，无催化剂、微波辐射的条件下，使吲哚-2-酮(1)和醛、酮(2)发 生缩合反应，合成了3-芳基亚甲基-1，3-二氢-2H-吲哚-2-酮类化合物，时间短、 收率高。     

Investigation of the reactivities and tautomerism of azolidines. 53. Synthesis of 5-arylidene-2-allylamino-δ2-thiazolin-4-ones and 5-arylidene-2-imino-3-allylthiazolidin-4-ones

Depending on the reaction conditions, 2-allylamino-5-arylidene-²-thiazolin-4-ones, 2-imino-3-allyl-5-arylidenethiazolin-4-ones, and 3-allyl-5-arylidene-thiazolidine-2,4-diones are obtained by condensation of 2-allylamino-²-thiazolin-4-one and 2-imino-3-allylthiazolidin-4-one with aromatic aldehydes.See [1] for communication 52.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 494–497, April, 1985.     

微波辐射下4-硫胸腺嘧啶核苷的合成研究

提出了一种高效合成3’,5’-O-二乙酰基-4-硫胸腺嘧啶核苷的方法,该方法具有反应时间短、操作简便等优点,目标产物产率可达93.9%以上。以二氧六环做溶剂,反应温度102℃,乙酰化胸腺嘧啶核苷与P2S5的摩尔比为1∶1.2,微波功率700W辐射8分钟,即可高收率得到3’,5’-O-二乙酰基-4-硫胸腺嘧啶核苷。     

Copper-catalyzed multicomponent reaction: facile access to functionalized 5-arylidene-2-imino-3-pyrrolines

The synthesis of a novel class of 2-imino-5-arylidene-3-pyrrolines via a copper-catalyzed multicomponent reaction of sulfonyl azides with alkynes and aziridines is described. The protocol is efficient and general.     

Solvent-free synthesis of 4-aryl substituted 5-alkoxycarbonyl-6-methyl-3,4-dihydropyridones under microwave irradiation

4-Aryl substituted 5-alkoxycarbonyl-6-methyl-3,4-dihydropyridones have been prepared in one-pot condensation from Meldrum's acid, methyl acetoacetate and the appropriate benzaldehyde in the presence of ammonium acetate using microwave irradiation without solvent. This rapid method produced pure products in high yields (81-91%) due essentially to a specific non-thermal microwave effect (17-28%) by conventional heating under the same conditions.     

A practical access to novel 2-amino-5-arylidene-1,3-thiazol-4(5H)-ones via sulfur/nitrogen displacement under solvent-free microwave irradiation

A new effective approach to the synthesis of a small library of 2-amino-5-arylidene-1,3-thiazol-4(5H)-ones was reported using solvent-free reaction conditions under microwave irradiation. In the first step, rhodanines were subjected to Knoevenagel condensation with aryl aldimines according to a facile one-pot protocol. Then the (5Z)-5-arylidene rhodanine derivatives were transformed directly into the corresponding 2-amino-1,3-thiazol-4(5H)-ones by sulfur/nitrogen displacement reaction under microwaves with retention of configuration and good overall yields.     

水溶液中微波辅助下5-碘嘧啶类化合物的合成

5-碘嘧啶类衍生物具有显著的化学治疗活性和有机合成用途。碘苷(又名疱疹净)于1962年被美国FDA批准用于治疗疱疹病毒角膜炎,这是第一个抗单纯疱疹病毒药物[1]。以碘苷为中间体可以合成其它高效低毒的抗病毒药物[2]。另外,通过Suzuki、Sonogashira等金属催化偶联反应可以在5位引     

One-pot synthesis of disperse dyes under microwave irradiation: dyebath reuse in dyeing of polyester fabrics

A series of 4-hydroxyphenylazopyrazolopyrimidine disperse dyes were prepared via one-pot reactions of p-hydroxyphenylhydrazone, hydrazine hydrate, and acetylacetone or enaminones using microwave irradiation as an energy source. Structural assignments of the dyes were confirmed by X-ray crystallographic structure determination. Instead of discharging the dyebath after each dyeing cycle, the residual dyebath was spectrophotometrically analyzed and then pH readjusted for a repeat dyeing with longer time. Fastness of the dyed samples was measured after each recycle. Most of the dyed fabrics tested displayed good light fastness and excellent fastness to washing and perspiration. Finally, the biological activity of the synthesized dyes against Gram positive bacteria, Gram negative bacteria and yeast were evaluated.     

One-pot multicomponent synthesis of novel thiazol-2-imines via microwave irradiation and their antifungal evaluation

Microwave-assisted green approach is developed for an efficient synthesis of thiazol-2-imines under catalyst-free conditions. The desired products are formed by one-pot three-component reaction which is an improvised method for Hantzsch thiazole synthesis. The microwave-assisted protocol gives excellent yields with high purity in just 10–15?min. All the synthesized compounds have been screened for antifungal activity and some of the derivatives show a broad spectrum against fungal pathogens.     

One-pot preparation of fluorinated propargylamines under microwave irradiation and solvent-free conditions

A facile one-pot method has been developed for the synthesis of fluorine-containing propargylamines by a three-component coupling of fluorinated aldehydes, amines, and alkynes, in the presence of copper (I) chloride under microwave irradiation and solvent-free condition. This process is an efficient alternative to traditional thermal reaction. All new compounds are fully characterized by spectral methods.     

One-pot two-step synthesis of 4-vinylphenols from 4-hydroxy substituted benzaldehydes under microwave irradiation: a new perspective on the classical Knoevenagel-Doebner reaction

The classical Knoevenagel-Doebner reaction is reinvestigated wherein the direct synthesis of substituted 4-vinylphenols instead of the expected 4-hydroxycinnamic acids is described. The condensation reaction is performed on 4-hydroxy substituted benzaldehydes and malonic acid with a mixture of acetic acid-piperidine as condensing agent under focused microwave irradiation. The occurrence of simultaneous condensation-double decarboxylation without the use of any decarboxylating agent is a new finding, the reaction being facilitated solely by the hydroxy substituent and microwave irradiation effect.     

微波辐射下有效合成缩氨基硫脲类化合物

将肼基二硫代甲酸甲酯与相应的醛或酮在微波辐射下,经2~3.5m in反应得到化合物3-二取代甲(乙)撑肼基二硫代甲酸甲酯1,收率90~96%,然后将化合物1与胺在微波辐射下,经35~45m in反应得到目标化合物2~4,收率68~90%。微波辐射法比常规法显著的缩短了反应时间,提高了收率。共计合成目标化合物19个。以上化合物均经过熔点测定、质谱、红外光谱、核磁共振氢谱对其结构进行确证。