Method of preparing quinolines, naphthyridines and other nitrogen bi-heterocyclic compounds
AssigneeDynamit Nobel Aktiengesellschaft
InventorKlaus-Dieter Steffen
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Abstract
A method for the preparation of nitrogen bi-heterocyclic compounds is disclosed involving the saponification of a compound of the formula ##STR1## wherein R, E, D, B, A, and R' have the previously assigned significance which comprises saponifying the same by contacting it with at least a stoichiometric amount of water followed by decarboxylation. The carboxylic acid esters can be those formed by cyclization of dicarboxylic acid esters such as alpha-picolylaminomethylenemalonic acid diethyl ester.
Claims21
A method for preparing a nitrogen heterocyclic of the formula ##STR7## wherein R=hydrogen, halogen, nitro, amino, keto, alkyl, alkenyl, substituted aryl, unsubstituted aryl, haloalkyl or aryl or alkyl substituents having a nitrogen, oxygen sulfur or SO.sub.2 moiety in the chain or in a cyclic arrangement;
- R'=hydrogen, aryl, alkyl, alkenyl or haloalkyl;
- A, B, D, E, represent nitrogen or carbon atoms with up to 3 of said A, B, and D, representing nitrogen and the balance representing carbon atoms;
- n is an integer from 0 to 4 which comprises saponifying a compound of the formula ##STR8## wherein R, E, D, B, A, and R' have the previously assigned significance by contacting the same with at least a stoichiometric amount of water in the presence of an acid catalyst in an amount of 0.05 to 3 weight percent under a pressure of 4 to 8 bars distilling out the alkanol, neutralizing the acid, and thereafter decarboxylating the so-saponified compound without isolating the product of saponification.
Dependencies are inferred from the claim text.