5,8-Dihydro-5-oxo-2-(4-or 3-pyridinyl)pyrido[2,3-d]pyrimidine-6-carboxylic acids and esters

US3992380A · kind A · utility

Assignee

• Sterling Drug, Inc. · US

Inventors

• George Y. Lesher · Rockville Centre, US
• Baldev Singh · East Greenbush, US

Key dates

• Filing date: Mar 3, 1975
• Grant date: Nov 16, 1976
• Expiry date: Mar 3, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D471/04
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Antibacterial 5,8-dihydro-8-(lower-alkyl)-5-oxo-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (I) where Z is carboxy or lower-carbalkoxy, R.sub.2 is hydrogen or lower-alkyl and Q is 4(or 3)-pyridinyl or 4(or 3)-pyridinyl having one or two lower-alkyl substituents is prepared by heating di-(lower-alkyl) N-(2-Q-6-R.sub.2 -4-pyrimidinyl)aminomethylenemalonate (III) to produce 5,8-dihydro-5-oxo-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (II) which is tautomeric with 5-hydroxy-2-Q-4-R.sub.2 -6-Z-pyrido[2,3-d]pyrimidine (IIA) where Q and R.sub.2 are the same as in I above and Z is lower-carbalkoxy, reacting II(or IIA) with a lower-alkylating agent to produce I where Z is lower-carbalkoxy and hydrolyzing this ester (I) to produce I where Z is carboxy. Alternatively, the acid (II or IIA where Z is COOH) can be alkylated after first hydrolyzing the ester (II or IIA where Z is lower-carbalkoxy). The preparations of the intermediate III and intermediates used in its preparation are given.