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1.
Efficient electrophilic substitution reactions of indoles with various aromatic aldehydes were carried out using a catalytic amount of ZnO under solvent‐free conditions to afford the corresponding bis(indolyl)methanes in excellent yields. Among the various methods published for the synthesis of bis(indolyl)methane, ZnO is a very cheap, environmentally friendly, and reusable catalyst that can be used for synthesis of a new range of bis(indolyl)methane derivatives.  相似文献   

2.
A series of 4‐arylidene‐2‐phenyl‐5(4)‐oxazolones were synthesized from cyclodehydration–condensation of hippuric acid, aromatic aldehydes, and acetic anhydride catalyzed by ytterbium(III) triflate under mild conditions in excellent yields.  相似文献   

3.
A simple and efficient synthesis of tert‐butyl ethers from various alcohols and substituted phenols using tert‐butyl bromide in the presence of basic lead carbonate as a catalyst. The catalyst is easily recovered via filtration and can be reused up to three times without appreciable loss of activity.  相似文献   

4.
Substituted iminoimidazolines were synthesized from a one‐pot reaction of aromatic or hetero‐aromatic amines with imidazolidine‐2‐thione under solvent‐free conditions using microwave irradiation with good to excellent yields.  相似文献   

5.
A novel method for the direct conversion of deoxybenzoin into 2‐alkyl‐4,5‐diphenyloxazoles and 2‐aryl‐4,5‐diphenyloxazoles has been developed using treatment of HTIB and nitriles under solvent‐free microwave irradiation conditions.  相似文献   

6.
Knoevenagel condensation of aromatic aldehydes with active methylene compounds under solvent‐free conditions to synthesize arylidene compounds by grinding in the presence of TEBA at room temperature has been described. This method is simple, efficient, and environmentally friendly.  相似文献   

7.
An efficient and environmentally friendly synthetic method for the synthesis of primary amides under microwave irradiation was described, in which the primary amine was directly reacted with acid without any catalytic agents. The reaction took place in 8–12 min, which was much shorter than the traditional synthetic methods, with almost quantitative yields. The influential factor of the reaction was discussed. The tautomerization between the carboxylic acid group and the H atom in α‐carbon of L‐amino acid was observed, presumably a dehydrated intermediate forming from this tautomerized isomer.  相似文献   

8.
A mild and efficient method has been developed for the preparation of acylals from aldehydes catalyzed by antimony trichloride under solvent‐free conditions in very good to excellent yields. The easy availability, low cost, and ease of handling of the catalyst make this procedure especially attractive for large‐scale synthesis.  相似文献   

9.
Simple N‐heterocycles were converted to N‐phosphono‐ and phosphinoxidomethyl derivatives by a solvent‐free microwave‐assisted condensation of the heterocycle, paraformaldehyde, and diethylphosphite or diphenylphosphine oxide in a convenient and, in most cases, efficient way. In contrast to an earlier report, imidazole proved to be unreactive in this type of phospha‐Mannich reaction.  相似文献   

10.
A convenient method for the synthesis of 3‐substituted quinazolin‐4(3H)‐ones using the convergent reactions of formic acid, a primary amine, and isatoic anhydride under solvent‐free conditions and with brief microwave irradiation is described.  相似文献   

11.
《合成通讯》2013,43(15):1997-2004
Abstract

Copper(II) bromide is found to be an efficient catalyst for the electrophilic substitution reaction of indole with aldehydes to afford the corresponding bis(indolyl)methanes in good yields.  相似文献   

12.
An operationally simple, efficient, and environmentally benign synthesis of 1,1‐diacetates in good yields by reaction of different aldehydes with acetic anhydride in the presence of PEG‐supported sulfonic acid under solvent‐free conditions is described.  相似文献   

13.
A variety of aromatic compounds are nitrated to the parent nitro aromatic compounds under solvent‐free conditions using supported tetramethylammonium nitrate/silicasulfuric acid as a useful reagent. This methodology is useful for nitration of activated and deactivated aromatic rings.  相似文献   

14.
Organosulfur compounds are useful materials and most of them have pharmacological properties. The sulfonic esters are important intermediates in organic synthesis and used as acaricides and thermal recording materials. The sulfonyl hydrazides are valuable as inhibitors, agrochemical fungicides, insecticides and photographic images. Some methods have been reported for preparing these compounds to date. Usually, these reactions were carried out in organic solvent[1,2]such as pyridine and DMF. Even up-to date solid-phase synthesis requires solvent. What's more, they have other drawbacks including long reaction time, producing much wastes and by-products, tedious experimental procedure.  相似文献   

15.
A simple, efficient, and general method has been developed for the synthesis of coumarin derivatives through a one‐pot reaction of aromatic aldehydes, 2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione and 5,5‐dimethyl‐1,3‐cyclohexanedione, in the presence of TEBA under solvent‐free conditions using grinding methods. The mild reaction conditions, simple protocol, high yields, and cleaner reaction make this protocol practical and economically attractive.  相似文献   

16.
In recent years, much attention has been directed towards the syntheses of 1,4-dihydropyridyl compounds due to the fact that 1,4-dihydropyridyl compounds possess a variety of biological activities.[1] In view of the importance of polyhydroquinoline derivatives, many classical methods for the synthesis of polyhydroquinoline derivatives were reported[2] by conventional heating and refluxing approaches in the presence of organic solvent. These methods, however, involve long reaction time, harsh reaction conditions, the use of a large quantity of organic solvent and unsatisfactory yields. Therefore,improvements in such syntheses have been sought continuously.  相似文献   

17.
We report a highly efficient, one‐pot, three‐component condensation of carbonyl compounds, amines, and TMSCN in MeCN; the reaction is significantly promoted by the catalytic amount of cerium(III) chloride at ambient temperature in excellent yields without any adverse effect on the other substituents. The method afforded an elegant alternative to the synthesis of α‐aminonitriles. The reactions are fast and clean, and the products obtained are of high purity.  相似文献   

18.
A range of tetrahydrobenzo[b]pyrans have been synthesized in very good yields under solvent‐free conditions by grinding α‐cyanocinnamonitrils or β‐cyano‐β‐carbethoxy styrene and 5,5‐dimethyl‐1,3‐cyclohexanedione in the presence of TEBA as catalyst. The short reaction time, cleaner reaction, and easy workup make this protocol practical and economically attractive.  相似文献   

19.
A facile parallel synthesis of 2‐amino‐4,6‐diarylbenzene‐1,3‐dicarbonitrile derivatives via a one‐pot reaction of aromatic aldehydes, aromatic ketone, and malononitrile under solvent‐free conditions has been developed. This new protocol has the advantages of shorter time, higher yields, lower cost, and environmental friendliness.  相似文献   

20.
The uncatalyzed and three‐component reaction of arylaldehyde, malonodinitrile, and 3‐arylamino‐5,5‐dimethylcyclohex‐2‐enone at 160 °C under solvent‐free conditions gave 1,4‐diarylquinoline derivatives in high yields.  相似文献   

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