A tandem multi-component synthesis of 5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones

Add time:08/19/2019    Source:sciencedirect.com

The five-component reaction of ethyl 2-[(2-oxopropyl)sulfanyl]acetate, aromatic aldehydes, and ammonium acetate affords two diastereomers of 5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones via a novel tandem Mannich-enamine-substitution sequence. Presumably, they are generated from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates. During the formation of the trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates, the configuration at the carbon bearing an aryl group adjacent to the enamide CC double bond is inverted via ring opening and closure. When o-substituted benzaldehydes were employed in this reaction, 5,7-diaryl-5,6-dihydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones were obtained via air oxidation, along with trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones.

We also recommend Trading Suppliers and Manufacturers of 2(1H)-Pyrimidinone, tetrahydro-1-(2-methyl-1-oxopropyl)- (cas 127834-94-0). Pls Click Website Link as below: cas 127834-94-0 suppliers

Prev:A facile and efficient synthesis of hexahydro-1H-pyrido[2,3-b]indol-2-one scaffolds via a sequential Michael addition/amidation/reductive cyclization process
Next:Synthesis of aryl substituted 2,4,5,6-tetrahydro-3H-1,2,4-triazepine-3-thiones/ones starting from chalcone-derived β-isothiocyanato ketones)