An efficient synthesis of 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid and some carbonyl derivatives of it and its 6‐acetyl homologue

Abstract

Starting with 1,1‐dimethoxy‐2‐propanone (1), 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid (5a) has been prepared in large quantities by a highly efficient, 4‐step synthesis. This compound, along with its one carbon homologue, 6‐acetyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid (5b) has been reacted with several carbonyl derivative forming reagents to provide a series of side chains for β‐lactams. Among these carbonyl derivatives are styrylamides which were prepared from Wittig and Horner‐Emmons reagents. The preparation of the phosphonium salts and phosphonate esters is also described.

Indanylidenes. 1. Design and Synthesis of (E)-2-(4,6-Difluoro-1-indanylidene)acetamide, a Potent, Centrally Acting Muscle Relaxant with Antiinflammatory and Analgesic Activity

“…Some of the indanylidenes were prepared directly from the indanone via the Wittig reaction. The corresponding carbamoyl phosphonates (methods D and H) or phosphonium chlorides (methods F and G) were prepared by reaction of the appropriately substituted 2-chloro- N -acetamide with triethyl phosphite or triphenylphosphine as depicted in Scheme . The ylides were generated by reaction of the phosphonates and phosphonium chlorides with sodium hydride or n -butyllithium.…”