Aroyl[bis(4-hydroxycoumarin-3-yl)]methanes in reactions with 1,2-diaminobenzenes

Abstract

The reaction of aroyl[bis(4 hydroxycoumarin 3 yl)]methanes with 1,2 phenylenediamines in Pr i OH is accompanied by the recyclization to 8 R or 7 R 4 (2 hydroxyphenyl) 1,5 benzodiazepin 2 ones, whereas the reaction with o phenylenediamine and its 4 methyl sub stituted derivatives in MeOH produces organic ionic salts of the bis coumarin anion with monoprotonated o phenylenediamine as the cation.Key words: aroyl[bis(4 hydroxycoumarin 3 yl)]methanes, 4 R 1,2 diaminobenzenes, 8 R (7 R) 4 (2 hydroxyphenyl) 1,5 benzodiazepin 2 ones, recyclization, ionic salts, X ray diffraction study.Various 4 hydroxycoumarin derivatives have found use as drugs. 1-5 Among these is neodicoumarin (ethyl di(4 hydroxycoumarin 3 yl)acetate), which is used in medicine as an anticoagulant. 6 These bis adducts based on heterocyclic CH acids and active carbonyl compounds (aldehydes or glyoxals) have attracted interest because their molecules contain several electrophilic centers, thus giving promise that various heterocyclization path ways are possible in the reactions with binucleophilic re agents.Earlier, 7 we have demonstrated that the reaction of aryl(aroyl)[bis(5,5 dimethyl 1,3 dioxocyclohexan 2 yl)]methanes with o phenylenediamine (o PDA) produces hexahydrobenzo[b,e] 1,4 diazepin 1 one derivatives 1A or 9 aryl(aroyl) 10 (2 aminophenyl)decahydroacridine 1,8 dione derivatives 2 depending on the electronic char acter of the substituent in the aryl or aroyl fragments. Electron withdrawing substituents in the aromatic moi ety facilitate the formation of the diazepine ring, whereas the formation of acridones is typical of the starting polyketones containing electron releasing substituents in the benzene ring.In the present study, we investigated the reaction of 4 R benzoyl[bis(4 hydroxycoumarin 3 yl)]methanes 3a-c with o PDA (4a) and its substituted derivatives 4b-d with the aim of synthesizing diazepines 1B, which are structurally similar to diazepines 1A and in which the diazepine fragment is annulated with the coumarin ring. The starting ketones 3a-c were synthesized in good yields by heating 4 hydroxycoumarin with p substituted aryl glyoxals in AcOH for a short period of time. Their struc tures were confirmed by 1 H NMR spectra, which show singlets for the methine protons at δ 6.2-6.4 and multi R = Ar, COAr

A facile and practical p-Toluenesulfonic acid catalyzed route to dicoumarols containing an Aroyl group

“…Results are given in Table 2 in which it is apparent that aryl glyoxals, including those bearing electron-poor and electron-rich substituents, were able to undergo this reaction. Compared with a previously reported method which has used AcOH as reaction media, 9 the present method provides environmentally safe conditions using water as solvent and p-TSA as catalyst to obtain the desired products with better yields than previous reported. Recently, organic synthesis on water has also been reviewed by Fokin and co-workers.…”

“…Traditionally, the most popular strategies towards the synthesis of dicoumarols start from salicylaldehyde and formaldehyde 6 and involve the biosynthesis of dicoumarol using micro-organisms such as Penicillium jenseni, 7 or require the Knoevenagel condensation of 4-hydroxycoumarins with carbonyl compounds using several catalysts. [8][9][10] For many years, chemical reactions in water have attracted the attention of chemists. 11 From an environmental and economic point of view, water as a solvent or media has many advantages and usually results in excellent efficiency and selectivity.…”

Uncatalyzed, One‐pot Synthesis of 3,3′‐(Benzylene)‐ bis(4‐hydroxy‐2H‐chromen‐2‐one) Derivatives under Thermal Solvent‐free Conditions

“…Literature survey shows that these bis-adducts based on heterocyclic CH acids and active carbonyl compounds have attracted interest in organic synthesis. 13 A plausible mechanism for this reaction is proposed in Scheme 2. As reported in the literature, first nuleophilic addition of 4-hydroxycoumarin to polar carbonyl bond of aldehydes gives I, followed by loss of H 2 O to afford II.…”

“…Products were characterized by comparison of spectroscopic data (IR, 1 H NMR, 13 C NMR spectra) and melting points with authentic samples. The NMR spectra were recorded on a Bruker Avance DPX 300 MHz instrument.…”

One-pot Synthesis of Novel Pyrano-Fused Coumarins Catalyzed by ZnO Nanoparticles

“…It is noteworthy to mention that these ZnO-catalyzed reactions showed the chemoselectivity toward pyranocoumarins 4 instead of biscoumarins 5 which was reported in the previous literature. 21 To determine suitable conditions, the preparation of 4a was selected as a model. In the first attempt, compound 4a was not produced in absence of catalyst even after 180 min.…”