title: General and rapid pyrimidine condensation by addressing the rate limiting aromatization.
abstract: The rate limiting aromatization within the condensation approach toward pyrimidines utilizing amidines and activated olefins was addressed to provide for a general and rapid process. A strong solvent effect was elucidated to affect the rate for the initial alkoxide elimination from the intermediate Michael adduct wherein polar aprotic solvents demonstrate an addition controlled aromatization. Spectroscopic studies support a solvent dependent equilibrium between the amidine and alkoxide base wherein the rate for aromatization is optimal when the equilibrium toward the amidine anion was strongly favored.
authors.affiliation: Chemical Development, Boehringer-Ingelheim Pharmaceuticals, Inc. , 900 Ridgebury Road/P.O. Box 368, Ridgefield Connecticut 06877-0368, United States.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Fandrick
authors.forename: Delia
authors.initials: D
authors.lastname: Reinhardt
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Desrosiers
authors.forename: Sanjit
authors.initials: S
authors.lastname: Sanyal
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fandrick
authors.forename: Shengli
authors.initials: S
authors.lastname: Ma
authors.forename: Nelu
authors.initials: N
authors.lastname: Grinberg
authors.forename: Heewon
authors.initials: H
authors.lastname: Lee
authors.forename: Jinhua J
authors.initials: JJ
authors.lastname: Song
authors.forename: Chris H
authors.initials: CH
authors.lastname: Senanayake
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000578:Amidines / Q000737:chemistry*; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis
chemical_list: D000475:Alkenes; D000578:Amidines; D011743:Pyrimidines; D012997:Solvents; C030986:pyrimidine