Isay reaction

{{Reactionbox

| Name = Isay reaction

| Type = Ring forming reaction

| NamedAfter = Oskar Isay

}}

The Isay reaction also known as Gabriel-Isay condensation is an organic reaction in which certain diaminopyrimidines are transformed into pterins by condensation with a 1,2-dicarbonyl compound, such as 2,3-butanedione.{{cite journal | first = Oskar | last = Isay | title = Eine Synthese des Purins | journal = Berichte der Deutschen Chemischen Gesellschaft | year = 1906 | volume = 39 | pages= 250–265 | doi = 10.1002/cber.19060390149| url = https://zenodo.org/record/1426174 }}.{{cite journal | pages= 3925–3927 | doi = 10.1021/jo00824a016 | title= Preparation of 6-substituted pterins via the Isay reaction | year= 1971 | last1= Kaufman | first1= Seymour | last2= Storm | first2= Carlyle B. | last3= Shiman | first3= Ross | journal= The Journal of Organic Chemistry | volume= 36 | issue= 25}}. The reaction is named after Oskar Isay.