New fluorescent compounds, benzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides (3a-g), 2-amino-4-methylsulfanylbenzo[4,5]thieno[3,2-d]pyrimidine (6), and 2-amino-4-methylsulfanyl-7-methoxybenzo[4,5]furo[3,2-d]pyrimidine (7), were synthesized in good yields from heterocyclic ketene dithioacetals (1a-c) and guanidine carbonate (2a) or (S)-methylisothiourea sulfate (2b) in pyridine under reflux. Among ...

Leishmania donovani and Leishmania braziliensis grown in culture formed millimolar concentrations of allopurinol ribonucleoside 5'-monophosphate from [6-14C]allopurinol. In addition, allopurinol 1-ribonucleoside, oxipurinol riboside 5'-monophosphate, and three new metabolites of allopurinol, namely, 4-aminopyrazolo(3,4-d)pyrimidine ribonucleoside 5'-monophosphate and the corresponding di- and t...

In the title compound, [Co(2)(NCSe)(4)(C(4)H(4)N(2))(3)(CH(3)OH)(2)](n), the Co(II) ion is coordinated by three N-bonded pyrimidine ligands, two N-bonded seleno-cyanate anions and one O-bonded methanol mol-ecule in an octa-hedral coordination mode. The asymmetric unit consists of one Co(II) ion, one pyrimidine ligand, two seleno-cyanate anions and one methanol mol-ecule in general positions as ...

An approach to the detection of pyrimidine dimer-DNA glycosylase activity in living cells is presented. Mutants of Escherichia coli defective in uvr functions required for incision of UV-irradiated DNA were infected with phage T4 denV+ or denV- (defective in the T4 pyrimidine dimer-DNA glycosylase activity). In the former case the denV gene product catalyzed the incision of UV-irradiated host D...

4,6-Diamino-1H-pyrimidine-2-thione (1) was used for the preparation of pyrimidine derivatives 2-5. Compound 5 was cyclized to produce pyrimido[2,1-b][1,3]thiazine derivative 6 which was condensed with p-chlorobenzaldehyde to give compound 7. The latter compound was reacted with hydroxylamine to give isoxazolo[4,5-d]thiazino[2,3-a]pyrimidine 8. Compound 8b was treated with 2-chloroethyl methyl e...

The title compound, C(4)H(4)N(6)S(2), was synthesized by the reaction of 3-mercapto-1H-1,2,4-triazole with sodium hydrox-ide in ethanol. The mol-ecule possesses a crystallographically imposed twofold axis. Inter-molecular N-H⋯N hydrogen bonds link the mol-ecules into chains along the c axis.

The schiff base ligand was prepared from furfuraldehyde with 4-amino-5-mercapto-5triazole and characterised. The metal complexes of Ti(III),V(III),Mn(III),Co(III) and Ru(III) derived from this ligand were characterised by elemental analyses, molar conductance,magnetic measurements, infra red 1H NMR & electronic spectral data. Based on these studies octahedral structures have been assigned to th...

Dimroth rearrangement in a thiadiazole—triazole system was first observed by Kindt—Larsen and Pedersen [1] when 5-mercapto-l-phenyl-l,2,3-triazole was formed from 5-anilino-l,2,3-thiadiazole. A similar rearrangement has been ob­ served to take place with 4-substituted 5-amino-l,2,3-thiadiazoles [2] and 4-acyl-5-arylamino-l,2,3-thiadiazoles [3]. In the present work the kinetics of the rearrangem...

The chain persistency of single-stranded (ss) DNA at a high-salt limit mainly arises from the so-called base-stacking interaction between consecutive bases along the strand. Stacking is appreciable for purine–purine (e.g., A–A) and purine–pyrimidine stacks (e.g., A–T), but it is weak for pyrimidine stacks (i.e., T–T, T–C, and C–C). We study how base stacking can stiffen the strand by classifyin...