Deb K. Das

Synthesis of fully-substituted pyridines and dihydropyridines in a highly chemoselective manner utilizing a multicomponent reaction (MCR) strategy

An efficient protocol has been developed for the synthesis of pyridines and 1,4-dihydropyridines based on chemoselective multicomponent reactions. Using readily available aldehydes, malononitrile and primary aliphatic amines, this procedure provides a divergent but straightforward access to a wide range of fully substituted pyridines and dihydropyridines via a primary amine based chemoselective strategy. Simple reaction procedure, good yields, mild reaction conditions, applicabilility to a wide range of substrates with the aid of chemoselectivity make this present protocol more innovative than existing ones.

Synthesis of fused tetrahydropyrido[2,3-c]coumarin derivatives as potential inhibitors for dopamine d3 receptors, catalyzed by hydrated ferric sulfate

Fused furo- and pyrano-tetrahydropyrido[2,3-c]coumarin derivatives were synthesized using one-pot three component reactions between aromatic aldehydes, 3-aminocoumarins and cyclic enol ethers in the presence of 10 mol% hydrated ferric sulphate [Fe2(SO4)3·xH2O] in refluxing acetonitrile. The salient features of the present protocol are good yields, high diastereoselectivities, application to a wide range of substrates, using an inexpensive, readily available and recyclable catalyst and environmentally benign reaction conditions.

A direct approach for the expedient synthesis of unsymmetrical ethers by employing bromodimethylsulfonium bromide (BDMS) mediated C–S bond cleavage of naphthalene-2-ol sulfides

The unsymmetrical ether derivatives 1-(alkoxy(aryl)methyl)naphthalen-2-ols (3a–q) were synthesized from 1-(aryl(alkyl/arylthio)methyl)-naphthalene-2-ol derivatives (1) and alcohols (2) by cleavage of C–S bond using bromodimethylsulfonium bromide (BDMS) at room temperature. Moreover, 1-(hydroxy(aryl)methyl)naphthalen-2-ol derivatives (7a–d) were also synthesized from the corresponding sulfide derivatives (1) on reaction with water using one equivalent BDMS. The direct synthesis of 3a was also achieved from β-napthol 5 by tuning the reaction conditions with overall one-pot two-steps sequence. Interestingly, the desired products 3a are not accessible directly from 2-naphthol, aromatic aldehyde and alcohol in the presence of BDMS at room temperature. Some of the salient features of this protocol are mild reaction conditions, good yields, operational simplicity and with a wide substrate scope.