ChemInform Abstract: Correlation of Ring Nitrogen Substituents with Carbon‐13 Nuclear Magnetic Resonance Data in Azoloazines.

1H{15N} GHMQC study of 5,7‐diphenyl‐1,2,4‐triazolo[1,5‐a]pyrimidine and 1H, 13C and 15N NMR coordination shifts in Au(III) chloride complexes of 1,2,4‐triazolo[1,5‐a]pyrimidines

“…Because 1a-3a were insoluble in CDCl 3 and decomposed in DMSO-d 6 , their NMR spectra were measured in DMFd 7 . In this solvent the 1 H signals were sharp and did not vary with time; hence one could assume that the discussed Au(III) complexes were stable.…”

“…13,14 The assignment of the 15 N resonances for 5,7-diphenyl-1,2,4-triazolo [1,5-a]pyrimidine (3) has also been proposed by us using 1D selective decoupling experiments. 15 In this paper, we present the 1 Hf 15 Ng GHMQC spectrum of 3 and the 1 H, 13 C and 15 N chemical shifts for 1-3 in DMF-d 7 . To the best of our knowledge these are the first NMR data for 1,2,4-triazolo [1,5-a]pyrimidines in this solvent.…”

Synthesis of Novel Heterocycle Systems: 6,8-Dimethyl-2-(Methylsulfanyl)-4-Amino-Substituted Pyrimido[4′,5′:3,4]Pyrazolo[1,5-a]Pyrimidine and 9,11-Dimethyl-5-(Methylsulfanyl)Pyrimido[2′,1′:5,1]Pyrazolo[4,3-e][1,2,4] Triazolo[4,3-c]Pyrimidine

“…Furthermore, the 1 H NMR spectra of compounds 7a-c confirmed the absence of any exchangeable hydrogens from NH and NH 2 groups. Mass spectra of these novel compounds showed the molecular ion peaks (M + 13 Note that the chemical shift of the proton or substituent at the 2-position for the [1,5c]pyrimidines (Scheme 5) was observed at higher field in comparison to those at the 3-position in the [4,3-c] isomers. 14,15 In addition, another important difference between these systems is apparent from the 13 C NMR data; thus C-2 in the [1,5-c] series is bonded to two adjacent ring nitrogens while [4,3-c] pyrimidine 7b was shifted to 146.13 ppm that corresponds to the upper limit for this carbon type.…”

2‐Aminopyridiniomethylphosphonite: A hydrogen‐bonded polymer from the hydrolysis of 1,3,4‐diazaphospholo[1,2‐a]pyridine

“…Together with the chemical shift of C-2 in 1 (613C = 133.2 [9]) it fits well into the linear SI3C/6 31P correlation for azoles and the corresponding azaphospholes [ 101. It also obeys the more general linear 614,15N/631P correlation for analogous di- coordinate nitrogen and phosphorus compounds [ I l l .…”

“…The introduction of a two-coordinate phosphorus in place of the 2-CH unit of 1 affects the shielding of the carbon atoms primarily in the five-membered ring. C-3 of 1 (6I3C = 112.9 [9]>, which is adjacent to phosphorus in 2, experiences a strong downfield shift, while C-9 (6I3C = 145.0 [9]) experiences a lesser one. The other carbon chemical shifts induced by the CH/P exchange are also positive but hardly significant.…”