An efficient stereo-controlled synthesis of bis-pyrimido-[4,5-d]-pyrimidine derivatives via aza-Diels–Alder methodology and their preliminary bioactivity

Abstract

An efficient stereo-controlled synthesis of bis-pyrimido-[4,5-d]-pyrimidine derivatives via aza-Diels-Alder methodology and their preliminary bioactivity3{

Experimental and numerical studies on gas tungsten arc welding of Ti–6Al–4V tailor-welded blank

“…The fracture mechanism for this study was taken from the Johnson-Cook model. This concept was widely used by the researchers to predict and study the fracture of metallic materials [31][32][33]. The material constants of the Johnson-Cook model were taken from the experimental work and are listed in Table 2.…”

Bicyclic 6 + 6 systems: the chemistry of pyrimido[4,5-d]pyrimidines and pyrimido[5,4-d]pyrimidines

“…In reuxing toluene and the absence of a catalyst, multicomponent one-pot aza-Diels-Alder reactions of terephthalaldehyde (174) with amines 175 and N 0 -(1,3-dimethyl-2,6-dioxo-1,2,3,6tetrahydropyrimidin-4-yl)-N,N-dimethylformimidamide (176) Scheme 61 Reactivity of chlorine atoms attached to the ring carbon atoms. gave the anticipated bis-pyrimidopyrimidines 177a-k in a procedure developed by Das et al 30 in another route, a catalytic amount of indium(III)triuoro-methane-sulfonate [In(OTf) 3 ] was used in chloroform for the successive multicomponent one-pot synthesis of bis-pyrimido-pyrimidines 177a-k through three reaction steps (Scheme 44).…”

“…23 Moreover, pyrimidopyrimidines are conveyed as receptors for tyrosine kinase 24 and have been applied in the biosynthesis of 5-phosphoribosyl-1-pyrophosphate. 25 Presently, the synthetic procedures of compounds that have a pyrimido [4,5-d]pyrimidine skeleton are variable using different routes, including: (1) the multicomponent condensation reaction of formaline with uracil analogs and amines which gives a product that has antidepressant activity; 22 and (2) several procedures including the three-component condensation of aryl aldehydes, amines such as aniline, aminouracil, thiocyanate salts or aminopyrimidine derivatives and active methylenes under catalytic conditions in a basic or acidic medium, [26][27][28][29][30][31][32][33][34][35][36][37][38] in addition to other reported synthetic approaches. 39,40 On the other hand, pyrimidopyrimidines were synthesized using a regiospecic one-pot reaction under solvent-free and microwave irradiation conditions.…”

Magnetically recoverable copper ferrite catalyzed cascade synthesis of 1,3‐dimethyl‐6‐nitro‐5‐arylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐diones under microwave irradiation and solvent‐less condition

“…So a plethora of reports have been found demonstrating efficient synthetic methodologies for organic molecules containing pyrido[2,3‐ d ]pyrimidine core structure starting from a diverse set of substrates employing homogenous, heterogeneous, and catalyst‐free procedures. [ 21–47 ] Among these, there are a good number of reports that describe excellent use of the diene nature of 6‐[(dimethylamino)methylene‐amino]‐1,3‐dimethyluracil ( 1 ) or related compounds to carry out [4 + 2] cycloaddition reactions with various electron deficient dienophiles for successful synthesis of pyrido[2,3‐ d ]pyrimidine derivatives. [ 21–28 ] Although a few of these reports demonstrate multicomponent methodologies to carry out the transformation in or without presence of homogeneous catalyst, [ 21–23 ] not a single report has been found to employ heterogeneous catalyst system for the purpose.…”