Piperonal → Methyl 4-(1,3-benzodioxol-5-yl)-1,2-dihydro-6-ethoxy-1-(2-methoxybenzyl)-2-oxoquinoline-3-carboxylate

Participants

Reaction Steps

A 50% solution of 0.4 g of 2-methoxybenzyl chloride ("A") in dichloromethane is added to a solution of 0.4 g of methyl 4-(1,3-benzodioxol-5-yl)-1, 2-dihydro-6-ethoxy-2-oxoquinoline-3-carboxylate (obtainable by reacting 1-amino-2-(3,4-methylenedioxybenzoyl)-4-ethoxybenzene and methyl chloroformylacetate in dichloromethane and ethyldiisopropylamine with subsequent cyclization of the intermediate in sodium methanolate solution, m.p. 224°-225°; 1-amino-2-(3,4-methylenedioxybenzoyl)-4-ethoxybenzene is obtainable by reacting 3,4-methylenedioxybenzaldehyde and N-(tert-butyloxycarbonyl)-p-ethoxyaniline, m.p. 113°-114°, in THF, tert-butyllithium at -78°, subsequently oxidizing the resulting 3', 4'-methylenedioxy-2-(N-tert-butyloxy-carbonylamino)-5-ethoxydiphenylmethanol and eliminating the amino protective group, EI-MS 285) in 5 ml of DMF and 0.17 g of potassium carbonate. The reaction mixture is stirred for 4 hours and worked up as usual. This results in the N-alkylation product methyl 4-(1,3-benzodioxol-5-yl)-1,2-dihydro-6-ethoxy-1-(2-methoxybenzyl)-2-oxoquinoline-3-carboxylate, m.p. 182°-183° and the -alkylation product methyl 4-(1,3-benzodioxol-5-yl)-6-ethoxy-2-(2-methoxybenzyloxy) quinoline-3-carboxy-late, m.p. 157°-158°.

Provenance & Evidence