Synthesis of 4-substituted-benzo[h]tetrazolo[1,5-a]-6,7-dihydroquinolines

918-91

A microwave promoted and Lewis acid catalysed solventless approach to 4-azasteroids

The preparation of 3-oxo-4-azasteroid fromA-nor-3,5-secosteroid-3-oic acid is described in a solventless condition catalysed by Lewis acid under microwave irradiation.We utilized urea as an environmentally benign source for the generation of ammonia for the aza cyclization reaction

Indium(III) trifluoromethanesulfonate: An efficient reusable catalyst for the alkynylation-cyclization of 2-aminoaryl ketones and synthesis of 2,4-disubstituted quinolines

An environmentally friendly and highly efficient procedure for the preparation of 2,4-disubstituted quinoline derivatives has been developed by a simple alkynylation 13cyclization reaction of 2-aminoaryl ketones with phenylacetylenes in the presence of indium( III) trifluoromethanesulfonate In(OTf)3 under microwave irradiation and solvent-free conditions. This catalyst can be recovered after the reaction and reused efficiently in subsequent runs

Microwave-promoted one-pot synthesis of 4H-thiopyrans from a,b-unsaturated ketones via a three-component reaction

—An efficient one-pot synthesis of substituted 4H-thiopyrans has been accomplished from a three-component reaction of a,b-unsaturated ketones, Lawesson’s reagent and alkynes under microwave irradiation

Baker's Yeast-catalysed ring opening of benzofuroxans : an efficient green synthesis of aryl-1,2-diamines

A simple and inexpensive method for the reductive cleavage of N–O bond of benzofuroxans with bakers’ yeast under nonfermenting condition in aqueous media was achieved. The procedure gives excellent yields of aryl-1, 2-diamines

Microwave promoted one-pot synthesis of novel A-ring fused steroidal dehydropiperazines

The preparation of ring-A fused steroidal dehydropiperazine at the 3,4-position is herein described. The novel steroidal dehydropiperazines were prepared from the annulation reaction of ethylenediamine with 3-keto-4-en steroids in a one-pot reaction under microwave irradiation. The key step involves base catalysed aerial oxidation of the C-6 methylene group followed by cyclocondensation of ethylenediamine via Michael addition reaction