Synthesis of Substituted Phenyl2-Aminopyridine-3-sulfonates

Abstract

A series of phenyl 2-aminopyridine-3-sulfonates 3 has been synthesized starting from phenyl cyanomethanesulfonate (5). Pinner reaction with 5 gave phenoxysulfonylketene aminal 4K which was cyclocondensed with a series of C 3 -biselectrophiles to yield the title compounds, which are of pharmaceutical and medicinal interest.

Orthoesters in heterocycle synthesis

“…Subsequent condensation of 156 with triethyl orthoformate and orthoacetate at 45 o C for 2 h afforded 6-methyl-and 3,6-dimethyl-4Hpyrido[2,3-e][1,2,4]thiadiazine-1,1-dioxides (157a) and (157b), respectively, in 38% and 87% yields (Scheme 43). 84 These targets were sought as selective potassium channel openers and were aza-isosteres of a known antihypertensive agent, but the overall yield was deemed insufficient for further development.…”