METHODS: CLOUD POINT EXTRACTION (CPE) PROCEDURE WAS DEVELOPED FOR DETERMINATION OF TRACE AMOUNTS OF TETRABUTYLAMMONIUM IODIDE (TBA). IN THIS RESEARCH TRITON X-114 (SURFACTANT) AND ORANG (II) (OR) ANIONIC DYE ARE USED FOR CLOUD POINT EXTRACTION OF TBA. THE EXTRACTED TBA+_OR- ION PAIR IN WATER-METHANOL MIXTURE WAS COLORED AND ITS ABSORBANCE WAS MEASURED AT 428 NM [1-3]...

ASCORBIC ACID (VITAMIN C, AA) PLAYS A KEY ROLE IN THE FORMATION AND MAINTENANCE OF COLLAGEN AND IS A POWERFUL ANTIOXIDANT THAT REACTS WITH REACTIVE OXYGEN SPECIES OR FREE RADICALS. IT STRENGTHENS AND PROTECTS THE IMMUNE SYSTEM, ENHANCES IRON BIOAVAILABILITY, AND IS THOUGHT TO HELP REDUCE CHOLESTEROL LEVELS...

BACKGROUND: TETRABUTYLAMMONIUM BROMIDE (TBAB) FORM SEMI-CLATHRATE HYDRATES WHICH ARE CRYSTALLINE AND SOLID COMPOUNDS [1, 2]. TBAB HYDRATE SLURRY DUE TO THEIR POTENTIAL AND HIGH THERMAL STORAGE CAPACITY IS ONE OF UNDERSTUDY CANDIDATES FOR AIR CONDITIONING [3]. …

THE OXIDATION OF ALCOHOLS TO THE CORRESPONDING CARBONYL COMPOUNDS IS A KEY REACTION IN ORGANIC SYNTHESIS. THE SELECTIVE OXIDATION OF ALCOHOLS TO ALDEHYDES ORKETONES IS A VERY IMPORTANT ORGANIC TRANSFORMATION, ESPECIALLY IN PREPARING OF SOME IMPORTANT PRECURSORS AND INTERMEDIATES FOR DRUGS, FINE CHEMICALS, VITAMINS AND FRAGRANCES [1]...

BACKGROUND: BENZIMIDAZOLE DERIVATIVES EXHIBIT SIGNIFICANT ACTIVITY AGAINST SEVERAL VIRUSES SUCH AS HIV [1], HERPES (HSV-1) [2], RNA [3], INFLUENZA [4], AND HUMAN CYTOMEGALOVIRUS (HCMV) [1]. THE WIDESPREAD INTEREST IN BENZIMIDAZOLE-CONTAINING STRUCTURES HAS PROMOTED EXTENSIVE STUDIES FOR THEIR SYNTHESIS. WHILE MANY STRATEGIES ARE AVAILABLE FOR BENZIMIDAZOLE SYNTHESIS, THERE ARE TWO GENERAL METHODS FOR THE SYNTHESIS OF 2-SUBSTITUTED BENZIMIDAZOLES. ONE IS THE COUPLING OF PHENYLENEDIAMINES AND CARBOXYLIC ACIDS OR THEIR DERIVATIVES (NITRILES, IMIDATES, OR ORTHOESTERS), WHICH OFTEN REQUIRES STRONG ACIDIC CONDITIONS, AND SOMETIMES COMBINES WITH VERY HIGH TEMPERATURES OR MICROWAVE IRRADIATION. THE OTHER WAY INVOLVES A TWO-STEP PROCEDURE THAT INCLUDES THE OXIDATIVE CYCLO-DEHYDROGENATION OF SCHIFF BASES, WHICH ARE OFTEN GENERATED FROM THE CONDENSATION OF PHENYLENEDIAMINES AND ALDEHYDES.METHODS: ALDEHYDE AND O-PHENYLENEDIAMINE WERE THOROUGHLY MIXED IN ETHANOL, THEN TETRABUTYLAMMONIUM HYDROGEN SULFATE AS CATALYST WAS ADDED, AND THE SOLUTION HEATED AND STIRRED AT ROOM TEMPERETURE FOR APPROPRIATE TIME .ALSO ALDEHYDE AND O-PHENYLENEDIAMINE WERE THOROUGHLY MIXED, AND THEN TETRABUTYLAMMONIUM HYDROGEN SULFATE AS CATALYST WAS ADDED, AND THE MIXTURE IRRADIATED IN A MICROWAVE OVEN AT HIGH POWER LEVEL (MONITORED BY TLC).

BACKGROUND: IN 1893 BIGINELLI REPORTED THE FIRST SYNTHESIS OF 3, 4-DIHYDROPYRIMIDIN-(1H)-ONES BY A VERY SIMPLE ONE-POT CONDENSATION REACTION OF AN AROMATIC ALDEHYDE, UREA AND ETHYL ACETOACETATE IN ETHANOLIC SOLUTION USING A CATALYTIC AMOUNT OF ACID [1]. THE DIHYDROPYRIMIDINONE CORE AND ITS DERIVATIVES FORM AN IMPORTANT CLASS OF COMPOUNDS, AS IT IS PRESENT IN A LARGE FAMILY OF NATURAL PRODUCTS WITH BROAD BIOLOGICAL ACTIVITIES AS ANTIHYPERTENSIVE, ANTIVIRAL, ANTITUMOR AND ANTI-INFLAMMATORY AGENTS AND AS CALCIUM CHANNEL BLOCKERS [2, 3]. SYNTHETIC STRATEGIES FOR THE DIHYDROPYRIMIDINONE NUCLEUS INVOLVE BOTH ONE-POT AND MULTISTEP APPROACHES. AT PRESENT, SEVERAL GENERAL METHODS ARE KNOWN FOR THE PREPARATION OF DIHYDROPYRIMIDINONES, USING VARIOUS LEWIS AND PROTIC ACIDS [4, 5].METHODS: A MIXTURE OF ETHYL ACETOACETATE OR ACETYLACETONE, ALDEHYDE, UREA OR THIOUREA, TETRABUTYLAMMONIUM HYDROGEN SULFATE AS CATALYST IN CH3CN WAS HEATED AND STIRRED UNDER REFLUX AND IRRADIATED IN A MICROWAVE OVEN AT HIGH POWER LEVEL.Y. THE PROGRESS OF REACTION WAS FOLLOWED BY TLC.