Synthesis of 2-arylamino substituted 5,6-dihydropyrido[2,3-d]pyrimidine-7(8H)-ones from arylguanidines.
A practical protocol was developed for the synthesis of 2-arylamino substituted 4-amino-5,6-dihydropyrido[2,3-d]pyrimidin-7(8H)-ones from α,β-unsaturated esters, malononitrile, and an aryl substituted guanidine via the corresponding 3-aryl-3,4,5,6- tetrahydropyrido[2,3-d]pyrimidin-7(8H)-ones. Such compounds are formed upon treatment of 2-methoxy-6-oxo-1,4,5,6-tetrahydropyridine-3-carbonitriles with an aryl substituted guanidine in 1,4-dioxane and are converted to the desired 4-aminopyridopyrimidines with NaOMe/MeOH through a Dimroth rearrangement. The overall yields of this three-step protocol are, generally speaking, higher than the multicomponent reaction, previously developed by our group, between an α,β-unsaturated ester, malononitrile, and an aryl substituted guanidine.
Grup d'Enginyeria Molecular, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain.
Iñaki
I
Galve
Raimon
R
Puig de la Bellacasa
David
D
Sánchez-García
Xavier
X
Batllori
Jordi
J
Teixidó
José I
JI
Borrell
D004146:Dioxanes / Q000737:chemistry; D006146:Guanidines / Q000737:chemistry*; D009570:Nitriles / Q000138:chemical synthesis*; D011743:Pyrimidines / Q000138:chemical synthesis*; D011744:Pyrimidinones / Q000737:chemistry*; D044366:Transition Temperature
D004146:Dioxanes; D006146:Guanidines; D009570:Nitriles; D011743:Pyrimidines; D011744:Pyrimidinones; C000945:dicyanmethane; C025223:1,4-dioxane