title: Microwave-promoted catalyst- and solvent-free aza-Diels-Alder reaction of aldimines with 6-[2-(dimethylamino)vinyl]-1,3-dimethyluracil.
abstract: A microwave-promoted aza-Diels-Alder reaction between 6-[2-(dimethylamino)vinyl]-1,3-dimethyluracil and aldimines has been developed for the construction of dihydropyrido[4,3-d]pyrimidines. Urea is effectively employed as an environmentally benign source of ammonia in the absence of any catalyst or solvent. The key step in the reaction is in situ generation and trapping of the reactive aldimine formed from urea and aldehyde by the diene system of the uracil. The reaction is clean, and excellent yields are obtained in a matter of a few minutes.
authors.affiliation: Medicinal Chemistry Division, CSIR-North-East Institute of Science & Technology, Jorhat, Assam 785006, India.
authors.forename: Rupam
authors.initials: R
authors.lastname: Sarma
authors.forename: Manas M
authors.initials: MM
authors.lastname: Sarmah
authors.forename: Dipak
authors.initials: D
authors.lastname: Prajapati
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D003500:Cyclization; D055772:Green Chemistry Technology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008872:Microwaves; D015394:Molecular Structure; D011743:Pyrimidines / Q000138:chemical synthesis*; D012545:Schiff Bases / Q000737:chemistry; D012997:Solvents; D013237:Stereoisomerism; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry*; D014508:Urea / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry*
chemical_list: C572569:6-(2-(dimethylamino)vinyl)-1,3-dimethyluracil; D000447:Aldehydes; D011743:Pyrimidines; D012545:Schiff Bases; D012997:Solvents; D014753:Vinyl Compounds; D014498:Uracil; D014508:Urea