The embryo of the sand-dollar (Echinarachnius parma) was exposed to various concentrations of fluorinated pyrimidines immediately after fertilization. FUDR (5-fluorodeoxyuridine) was most active, and a concentration of 2 to 4 mgamma/10 cc. (0.8 to 1.6 x 10(-6) m.eq./liter) blocked development at the early blastula stage. Larger doses interrupted development at the same stage. This effect was pr...

A new synthetic route leading to functionalized 1H-1,2,3-triazole-4-carbonitriles has been developed. set of 1-aryl-5-methyl-1H-1,2,3-triazole-4-carbonitriles was obtained in high yields from readily available starting 1H-1,2,3-triazole-4-carboxylic acids via several protocols. Synthesized were examined as promising precursors the simple and efficient method for preparation 2-triazol-4-yl-thien...

o-Aminonitrile or o-aminoester compounds were cyclized to fused pyrimidines by reacting with ethyl iso(thio)cyanatoacetate in pyridine, and then were methylated, halogenated and subsequently displaced by the amines studied.

A series of 21 substituted pyrazolo[3,4-d]pyrimidines-4-amines were studied by (1)H and (13)C NMR. The application of two-dimensional techniques, HMQC and HMBC, allowed the complete assignment of the spectra for all the compounds.

One of the main directions steroid research is preparation modified derivatives in which, addition to changes physicochemical properties, receptor binding significantly altered, thus a bioactivity different from that parent compound predominates. In frame this work, 2-arylidene were first synthesized by regioselective modification A-ring natural sex hormone, 5α-dihydrotestosterone (DHT). After ...

A novel one-flask synthetic method was developed in which 5-aminopyrazoles were reacted with N,N-substituted amides in the presence of PBr₃. Hexamethyldisilazane was then added to perform heterocyclization to produce the corresponding pyrazolo[3,4-d]pyrimidines in suitable yields. These one-flask reactions thus involved Vilsmeier amidination, imination reactions, and the sequential intermolecul...