Background 1 3 (chalcones) are well known for his or her diverse array of bioactivities. protocol has been applied to a variety of substituted aryl carbonyls with superb yield of substituted 1 3 Results In a different way substituted chalcones were synthesized using iodine impregnated neutral alumina as catalyst in 79-95% yield in less than 2 minutes time under microwave activation without using any solvent. The reaction Tipifarnib was analyzed under different catalytic conditions and it was found that molecular iodine supported over neutral alumina gives the best yield. The otherwise hard single step condensation of hydroxy substituted aryl carbonyls is an attractive feature of this protocol to obtain polyhydroxychalcones in superb yields. In order to find out the general applicability of this new endeavor it was successfully applied for the synthesis of Tipifarnib 15 different chalcones including highly bioactive prenylated hydroxychalcone xanthohumol. Summary A new simple and solvent free method was developed for the synthesis of substituted chalcones in environmentally benign way. The slight reaction conditions easy work-up clean response profiles render this process as a fascinating replacement for the existing strategies. History 1 3 (chalcones) display a broad spectral range of natural activities . They are the primary precursor in the biosynthesis of flavonoids  loaded in edible plant life. They have already been reported showing various pharmacological pursuits like anticancer [3 4 antimalarial  anti-inflammatory  anti-tubercular  cytotoxic  gastroprotective  modulation of nitric oxide creation  etc. These compounds are essential synthons for the planning of five and six membered band systems  Rabbit Polyclonal to USP15. aswell as intermediate in the formation of many pharmaceuticals . Having such a mixed pharmacological activity and artificial utility chalcones possess attracted chemists to build up newer approaches for their synthesis. The most popular method of synthesis of chalcone may be the Claisen-Schmidt condensation of a proper acetophenone with benzaldehyde in Tipifarnib existence of aqueous bases like NaOH [13-15] KOH  Ba(OH)2 [17 18 etc. Various other base catalysts such as for example magnesium t-butoxide  potassium carbonate  alumina  MgO  calcinated hydrotalcites [23 24 organic phosphate/NaNO3 [25 26 KF/organic phosphate  and piperidine  are also used because of their synthesis. The many actions of chalcones are generally dependent on the quantity and positions of hydroxy methoxy and various other substituent groupings in Tipifarnib both A and B bands . Hydroxy chalcones will be the primary synthon for the formation of a accurate variety of naturally occurring bioactive flavonoids . Literature data unveils that existence of hydroxyl substituent over the benzaldehyde aromatic band hinders the bottom catalyzed aldol response. Tipifarnib This is really because from the reduced reactivity from the carbonyl component because of the delocalization from the phenoxide anion shaped . Hence it is needed to use safeguarding groups to avoid the forming of the phenoxide ion in the planning of hydroxychalcones under simple conditions [31 32 This problem can be conquer by using acidity catalysts like HCl BF3 B2O3 PTSA SOCl2/EtOH  AlCl3  BF3-Et2O  TiCl4  zeolites  RuCl3  Bronsted acidic ionic liquids  and H2SO4 Tipifarnib in AcOH  but many of them suffer from the drawbacks of lower yields and harsh environmentally detrimental reaction conditions. In an ongoing project on the synthesis of bio-active molecules we required a number of hydroxychalcones. The results acquired using existing methods were not acceptable. We therefore tried some fresh catalysts for this conversion including iodine-alumina because of our previous experience of using iodine as an inexpensive nontoxic readily available catalyst in many additional reactions [40-44]. Due to stringent and growing environmental regulations the chemical market needs the development of more eco-compatible synthetic methodologies . The use of heterogeneous catalysts under solvent free circumstances represents a possibly precious and clean path to a variety of natural products . Microwave helped artificial reactions are attaining importance lately due to its endorsement under Green chemistry process [47 48 We discovered iodine-alumina to become a fantastic catalyst for the.