2- perimidine

Similarly, the isolated salt 39 reacts with naphthalene-1,8-diamine in dichloromethane at room temperature to afford the 2,3-dihydro-l//-perimidine 78 in 85% yield (92SC3141) (Scheme 24). 

Analog ist der Aufbau von kondensierten Pyrimidinderivaten mit Hilfe von s-Triazin moglich, wie am Beispiel der Synthese des Perimidins (LXII) gezeigt werden konnte (24). 

Kim SH, Kim JH, Cui JZ, Gal YS, Jin SH, Koh K (2002) Absorption spectra, aggregation and photofading behaviour of near-infrared absorbing squarylium dyes containing perimidine moiety. Dyes Pigm 55 1-7... 

New heterocyclic ketene aminals have been obtained in yields ranging from 60 to 94% [89] starting from ethyl lff-perimidine-2-acetate or acetonitrile and isocyanates (Scheme 8.63). 

Bazureau described a tandem conjugate addition-intermolecular hetero-Diels-Al-der reaction of perimidine derivatives under solvent-free conditions with focused microwave irradiation [77]. The main feature of this reaction was attainment of complete addition in less than 8 min. When the reaction mixture was heated in an oil bath set at the same temperature for the same time the results were analogous (Scheme 9.27). 

Related to this ring system is [l,2,4]triazino[4,3-a]perimidine where the same face of the triazine again is involved in ring fusion. Heating... 

Perimidine was formed in the strongly exothermic reaction of 1,8-diami-nonaphthalane and EMME (67N115). 

Sudan Black B 2,3-Dihydro-2,2-dimethyl-6-[[4-(phenyl)azo-lH-perimidine... 

Thiol-thioxo tautomerism Amino-imino tautomerism Perimidine... 

Pyrimidine 1 is the lUPAC accepted name for 1,3-diazabenzene, while quinazoline 2 is the accepted name for benzo[r lpyrimidine or 1,3-diazanaphthalene. Perimidine 3 is the lUPAC accepted name for l//-benzo[r/ ]quinazoline or H -naphtho[l,8-r/i ]pyrimidine, while benzo. 4]perimidine 4 is also known as 1,3-diazapyrene. 

Coverage of perimidine chemistry can be found in two review articles <1981RCR816, 1995AQ151>, while benzo[g/5]perimidine chemistry is discussed in a review of diazapyrenes <2003CHE1417>. 

As described in CHEC-11(1996), pyrimidine has one axis of symmetry, about the 2,5-axis, and has three different pairs of bond lengths and four different bond angles <1996CHEC-11(6)93>. 8ymmetry is lost on unequal substitution at the 4-and/or 6-position, and accordingly quinazoline lacks the symmetry of pyrimidine. Perimidine is symmetrical about the 2-position because of proton isomerization (prototropy), but this symmetry is lost on substitution other than at the 2-position. 

Hydroxy, thiol, and amino groups in pyrimidine exist in tautomeric equilibria with their oxo, thioxo, and imino forms. An amino group in an electrophilic position exists predominantly as such, and the compound is named as an amine. Pyrimidines with a hydroxy or thiol group in an electrophilic position are dominated by the oxo or thioxo forms and are named as such, or with -one or -thione suffixes, if these are the principal groups. In the benzenoid 5-position, these derivatives are mainly present in the hydroxy, thiol, or amino forms and are named as such. Similar considerations apply to the nomenclature of quinazolines and perimidines <1996CHEC-II(6)93>. 

Figure 1 Electron distribution diagrams for pyrimidine 10, quinazoline 11, and perimidine 12.

Proton nuclear magnetic resonance (NMR) data for pyrimidines was reviewed in CHEC(1984) together with C and NMR data, and NMR data for quinazoline and perimidines was discussed in CHEC-11(1996). A tabulation of H, N, and N NMR data for simple pyrimidines is available in the book by Brown <1994HC(52)1>. N... 

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