MESOPOROUS SILICA CONTAINING SPECIFIC FUNCTIONAL GROUPS HAVING A HIGH SPECIFIC SURFACE AREAS AND POROSITIES THAT OPENED A WIDE FIELD OF APPLICATIONS IN REMOVAL OF TOXIC METAL IONS FROM WASTEWATER AND NATURAL-WATERS [1]. THUS THEY PROVIDE A SUITABLE APPROACH TO THE DEVELOPMENT OF GREEN CHEMISTRY PRINCIPLES.

THE KNOEVENAGEL REACTION IS A COMMON SYNTHETIC METHOD FOR FORMING CARBON-CARBON DOUBLE BONDS. IT HAS BEEN USED FOR THE PREPARATION OF A WIDE RANGE OF SUBSTITUTED ALKENES AS INTERMEDIATE FOR SYNTHESIS OF SOME PRODUCTS SUCH AS COUMARINS, PYRIDINES AND BENZOPYRANS.KNOEVENAGEL REACTIONS ARE CATALYZED WITH ACIDS OR BASES. PREVIOUSLY, AMINES, SODIUM ETHOXIDE [1], ZEOLITES [2] AND IONIC LIQUIDS [3] HAVE BEEN USED TO CATALYZE THESE REACTIONS. IN OUR LABORATORY, SUPPORTED LEWIS ACIDS WERE APPLIED FOR PROMOTION OF VARIOUS ORGANIC REACTIONS. IN THIS WORK WE HAVE PREPARED NANO-AL2O3/BF3 AND DETERMINED THE STRUCTURAL CHARACTERS BY FT-IR, XRD AND SEM.IN THIS WORK WE HAVE APPLIED NANO-AL2O3/BF3 FOR PROMOTION OF KNOEVENAGEL REACTION. VARIOUS ALDEHYDES WERE CONDENSED WITH ACTIVE METHYLENE COMPOUNDS SUCH AS MALONONITRILE, DIMEDONE AND BARBITURIC ACID IN ETHANOL AT ROOM TEMPERATURE. WE HAVE FOUND THAT TIME OF REACTION DEPENDS ON THE CHOSEN ALDEHYDE, AND IT CANNOT BE GENERALIZED. THE REUSABILITY OF CATALYST, GREEN CONDITION, ROOM TEMPERATURE AND EASY WORK-UP ARE SOME OF THE ADVANTAGE OF THIS PROTOCOL.

BACKGROUND: KNOEVENAGEL CONDENSATION IS A NUCLEOPHILIC ADDITION OF AN ACTIVE HYDROGEN COMPOUND TO A CARBONYL GROUP FOLLOWED BY A DEHYDRATION REACTION IN WHICH A MOLECULE OF WATER IS ELIMINATED [1]. MANY CATALYST HAVE BEEN REPORTED TO PROMOTE THJIS TRANSFORMATION. ALTHOUGH THERE ARE MANY REPORTS ON THE CONDENSATION REACTION BETWEEN 1, 3-DIKETONE AND ALDEHYDE WE HAVEN‘T ANY METHOD FOR CONDENSATION OF GLYOXAL DERIVATIVES WITH ALDEHYDE. HERE WE REPORT A SIMPLE ROUTE TO UNSATURATED KETONES BY REACTION OF ARYL GLYOXAL MONOHYDRATES WITH ACETYL ACETONE OR DIMEDONE IN WATER AS SOLVENT. THE PROCEDURE IS SIMPLE AND PRODUCTS WERE ISOLATED AND PURIFIED BY SIMPLE FILTRATION AND WASHING IN HIGH YIELDS.METHODS: THE ARYGLYOXAL AND DIKETONE WERE TREATED IN WATER AS A 1:1 MOLE RATIO MIXTURE. AFTER 1 DAY STIRRING AT ROOM TEMPERATURE, THE SOLID WAS FILTRATED AND WASHED WITH WATER TO AFFORD THE PURE PRODUCT.

CARBON-CARBON BOND FORMATION REACTION IS ONE OF THE MOST IMPORTANT REACTION IN ORGANIC SYNTHESIS [1]. KNOEVENAGEL CONDENSATION IS ONE OF THE MOST USEFUL AND WIDELY EMPLOYED REACTIONS FOR CARBON-CARBON BOND FORMATION IN ORGANIC SYNTHESIS [2]. GENERALLY, KNOEVENAGEL REACTIONS ARE CARRIED OUT BY THE CONDENSATION OF ACTIVE METHYLENE COMPOUNDS WITH ALDEHYDES USING SOME CATALYSTS SUCH AS SOME BASES, THEIR SALTS, LEWIS ACIDS AND IONIC LIQUIDS IN THE PRESENCE OR SOLVENT FREE SYNTHESIS...

THE KNOEVENAGEL CONDENSATION IS A USEFUL CARBON-CARBON BOND FORMING REACTION WITH NUMEROUS APPLICATIONS IN THE SYNTHESIS OF FINE CHEMICALS, HETERO-DIELS-ALDER REACTIONS AND IN THE SYNTHESIS OF CARBOCYCLIC AS WELL AS HETERO CYCLIC COMPOUNDS [1]. …

THE KNOEVENAGEL CONDENSATION IS ONE OF THE MOST USEFUL CARBON – CARBON BOND FORMING REACTION IN ORGANIC SYNTHESIS. THIS REACTION OBTAINS A-B UNSATURATED COMPOUNDS [1]. THESE PRODUCTS HAVE BEEN WIDELY USED AS INTERMEDIATES IN THE SYNTHESIS OF THERAPEUTIC DRUGS [2], FUNCTIONAL POLYMERS [3] AND FINE CHEMICALS [4]. HEREIN WE REPORT THE SUITABILITY OF EMPLOYING L-SERINE AS A GREEN CATALYST FOR KNOVENAGOL CONDENSATION UNDER SOLVENT FREE CONDITION. A MIXTURE OF ETHYL CYANOACETATE OR MALONONITRILE AND ALDEHYDES IN THE PRESENCE OF AMINO ACID WAS STIRRED AT 90OC TEMPERATURE FOR A WHILE. THE PROGRESS OF REACTION WAS MONITORED BY THIN LAYER CHROMATOGRAPHY (TLC). ON COMPLETION THE CRUDE PRODUCT WAS PURIFIED BY RECRYSTALLIZATION FROM HOT ETHANOL. AFTER CONDUCTING SEVERAL EXPERIMENTS, WE FOUND THAT THE SOLVENT FREE CONDITION WITH 80MOL% LOADING OF CATALYST AT 90OC LEADS TO THE BEST RESULT.

BACKGROUND: ORGANIC REACTIONS UNDER AQUEOUS CONDITIONS HAVE INCREASINGLY ATTRACTED CHEMISTS’ INTERESTS, PARTICULARLY FROM THE VIEWPOINT OF GREEN CHEMISTRY. AS AN IMPORTANT CARBON-CARBON BOND FORMING REACTION, KNOEVENAGEL CONDENSATION HAS BEEN EXTENSIVELY STUDIED THAT DISCOVERED BY E. KNOEVENAGEL IN 1896 [2]. THIS REACTION HAS BEEN USED FOR THE PREPARATION OF A WIDE RANGE OF SUBSTITUTED ELECTROPHILIC ALKENES AND FOR THE SYNTHESIS OF INTERMEDIATE [3]. AS A RESULT OF THEIR IMPORTANCE A LARGE NUMBER OF METHODS FOR THE KNOEVENAGEL CONDENSATION HAVE BEEN REPORTED [4]. BUT IT IS NOTEWORTHY TO OBSERVE THAT ALL THESE PROTOCOLS HAVE SOME DRAWBACKS, SUCH AS USE OF EXPENSIVE CATALYST, HIGH TEMPERATURE, LONG REACTION TIME, DISPOSAL OF TOXIC SOLVENTS AND CATALYST. THEREFORE, MANY EFFORTS HAVE BEEN MADE TO INTRODUCE NEW METHODOLOGIES THAT ARE MORE EFFICIENT, ECONOMICAL, AND COMPATIBLE WITH THE ENVIRONMENT...