@article {42544, title = {Continuous flow doebner{\textendash}miller reaction and isolation using continuous stirred tank reactors}, journal = {Organic Process Research \& Development}, volume = {20}, year = {2016}, month = {AUG}, pages = {1621{\textendash}1625}, abstract = {

Continuous flow Doebner{\textendash}Miller synthesis of different quinaldines from respective anilines is demonstrated using sulfuric acid as a homogeneous catalyst. The extent of reaction was monitored for various parameters, namely, temperature, residence time, mole ratio of sulfuric acid to substrate, mole ratio of crotonaldehyde to substrate, and so forth. Continuous stirred reactors in series were used as a preferred configuration for this rection that generates byproduct in the form of sticky solid material. The approach has been extended for six different anilines, and the results are compared with batch reactions. Continuous stirred reactors in series with distributed dosing of crotonaldehyde facilitated a continuous flow reaction with lower byproduct formation, increased yields, and continuous workup and is a scalable approach.

}, doi = {10.1021/acs.oprd.6b00179}, author = {Yadav, Maruti B. and Kulkarni, Sourabh and Joshi, Ramesh A. and Kulkarni, Amol A.} } @article {46854, title = {Novel synthesis of 3-((benzo[d]thiazol-2-ylamino)(phenyl)methyl)-4-hydroxy-1-methylquinol in-2(1H)-one via consecutive C-C and C-N bond formation in water}, journal = {Research on Chemical Intermediates}, volume = {46}, year = {2020}, month = {AUG}, pages = {3801-3815}, type = {Article}, abstract = {

A simple, efficient, and eco-friendly protocol has been developed for the synthesis of novel 3-((benzo[d]thiazol-2-ylamino)(4-methoxyphenyl)methyl)-4-hydroxy-1-met hylquinolin-2(1H)-one derivatives using a one-pot C-C and C-N bond forming strategy from the reaction of 4-hydroxy-1-methylquinolin-2(1H)-one, 2-aminobenzothiazole and aromatic aldehydes in aqueous solvent without using any metal catalyst. Several advantages of this protocol include its operational simplicity, short reaction time, mild reaction condition, efficient utilization of all the reactants, wide functional group tolerance, using water as an environmentally friendly solvent and non-chromatographic purification procedure. [GRAPHICS] .

}, keywords = {4-Hydroxy-1-methylquinolin-2(1H)-one, Green solvent, Multicomponent reactions (MCRs), Quinolines, Thiazole}, issn = {0922-6168}, doi = {10.1007/s11164-020-04173-0, Early Access Date = MAY 2020}, author = {Yadav, Maruti B. and Vagh, Sandip S. and Jeong, Yeon Tae} } @article {48027, title = {Divergent annulation of spiro[indoline-pyran] and fused (Epoxyetheno)indeno-furan from 1,2-diketone and 1-cyanoketone}, journal = {European Journal of Organic Chemistry}, volume = {2022}, year = {2022}, month = {AUG}, pages = {e202101534}, type = {Article}, abstract = {

A simple and efficient method for the construction of spiro[indoline-pyran] and fused (epoxyetheno)indeno[1,2-b]furan compounds from 1-cyanoketones and 1,2-diketone has been developed. The synthesis proceeded via the Knoevenagel and Michael adduct through intramolecular/Paal-Knorr cyclization under similar reaction condition. The less commonly used 1-cyanoketones and active carbonyl compounds served as the indole containing pyran and bicyclic furan source for the preparation of a new series of heterocyclic compounds. This heterocyclic structure allows one and more than one tetra-substituted carbon center and sequential hexa- and penta-cyclic core under very mild conditions and shows excellent chemo and regioselectivity. In addition, the synthesis of spiro[indoline-pyran] and (epoxyetheno)indeno[1,2-b]furan was demonstrated in a gram scale.

}, keywords = {Diverse synthesis, Intramolecular, Knoevenagel and Michael adduct, molecular diversity, Oxygen heterocycles, Paal-Knorr cyclization}, issn = {1434-193X}, doi = {10.1002/ejoc.202101534}, author = {Yadav, Maruti B. and Vagh, Sandip S. and Jeong, Yeon Tae} }