2-Chloro-8-methylquinoline-3-carboxaldehyde acts as a reagent in the synthesis of 2-Azetidinones from 2-chloro-8-Me-3-quinolinecarbaldehyde as potential antimicrobial agents, preparation and antibacterial activity of thiazoloquinoline Schiff bases as potential antibacterial agents.
0.3 mol of aniline, 40 mL of glacial acetic acid and 0.4 g of zinc powder were added to a round-bottomed flask fitted with a fractionating column and a thermometer mounted at the top of the column, and the evaporated water and acetic acid were collected in a beaker. The water and acetic acid were collected in a beaker and slowly heated for 15 min and then distilled at about 105 C. When the temperature kept decreasing, the heating was stopped and the end point was reached. The reaction was poured into ice water under stirring conditions while still hot to precipitate a solid, cooled, and filtered by pumping to give crude acetanilide, which was recrystallized with water to give white, pure 2-methylacetanilide.
The product obtained in the previous step 2-methylacetanilide 0.05 mol, DMF 0.15 mol was added to a four-necked flask, fitted with a thermometer, mechanical stirrer, condenser tube, mechanical stirring in an ice bath at a temperature of less than 10 , slowly added 0.35 mol of POCl 3 dropwise, the temperature was raised to 75 after the completion of dropwise addition and stirred the reaction for 12 h, the color was changed from a light yellow oily liquid to an orange-red liquid, and the reaction was completed. After the reaction was complete, the heating was stopped, and the reactants were slowly poured into 400 mL of ice water with stirring, left to stand, and the precipitated solid was filtered, washed with water for three times, dried in air, and then recrystallized from ethyl acetate to obtain the light-yellow needle-like crystals of 2-chloro-8-methylquinoline-3-carbaldehyde. 2-Chloro-8-methylquinoline-3-carboxaldehyde prepared by acetanilide cyclosynthesis was characterized by mass spectrometry, elemental analysis, infrared, and nuclear magnetic resonance spectroscopy as follows: light yellow acicular crystals, 90% yield, mp. 150-152 C.
