2-Nitrobenzaldehyde → HCID 20192976, compound

Participants

Reaction Steps

23.0 g of aminocrotonic acid methyl ester and 40.8 g of methylsulphonylacetone are added to 30.2 g of o-nitrobenzaldehyde dissolved in 200 ml of hexamethylphosphoric acid triamide. The mixture is then stirred for 3 hours at a bath temperature of 90°-100° C. The mixture is cooled and dissolved in 1,000 ml of ethyl acetate and the solution is washed with 400 ml of half-saturated sodium chloride solution, with twice 200 ml of 2 N sodium carbonate solution and with twice 500 ml of water. The ethyl acetate solution is dried with sodium carbonate and evaporated. Crystallisation of the residue from ethyl acetate/ether gives 2,6-dimethyl-3-carbomethoxy-5-methylsulphonyl- 4-(2-nitrophenyl)- 1,4-dihydropyridine of melting point 211°-212° C.

Provenance & Evidence