In the crystal structure of the title compound, C(13)H(11)N(4)O(3) (+)·Cl(-), the dihedral angle between the two pyridine rings is 9.72 (9) Å. Ions are linked via N-H⋯Cl, O-H⋯Cl and O-H⋯O hydrogen bonds, forming a three-dimensional framework.

A reflectron time-of-flight mass spectrometer (RTOFMS) with a laser ablation ion source was used to determine the isotopic ratio of 10B/11B present in boric acid solutions, using graphite as the matrix. The atom % 10B values obtained were within +/-1% of the actual ones. The determination of the boron isotopic ratio using this method is, in comparison to other methods, faster, less expensive an...

BACKGROUND The utility of N-heterocyclic bases to obtain molecular complexes with carboxylic acids is well studied. Depending on the solid state interaction between the N-heterocyclic base and a carboxylic acid a variety of neutral or ionic synthons are observed. Meanwhile, pyridines and pyrimidines have been frequently chosen in the area of crystal engineering for their multipurpose functional...

Pyromellitic dianhydride 1 was used as starting compound for the synthesis of some new derivatives of condensed dipyrrole, dibenzoxazine, and dipyridazine. Thus, the diimide 2 was formed on fusion of 1 with urea, thiourea and/or thiosemicarbazide. Also, 1 reacted with benzylamine to give terephthalic acid derivative 3 which on fusion afforded the cyclic diimide 4. The reaction of 1 with o-amino...

A series of β,β'-bicyclo-3,5-diaryl-BODIPYs were synthesized from the corresponding β,β'-bicyclo-3,5-diiodo-BODIPYs (1a,b) via Pd(0)-mediated Suzuki cross-coupling reactions in 82-92% yields. Subsequent aromatization with DDQ afforded the corresponding β,β'-dibenzo-aryl-BODIPYs, which showed red-shifted absorptions and emissions in the near-IR range. The dibenzo-appended BODIPYs showed characte...

Lividamine and paromamine were converted into two key intermediate ethylenic aldehydes 10a and 10b. Reductive amination of the two aldehydes yielded the protected sisamine 11a and the three analogs 11b, 12a and 12b. These four derivatives were deprotected to yield the four pseudodisaccharides 1a, 1b, 2a and 2b which were less active in vitro than neamine against Escherichia coli ATCC 9637 and S...