This invention is related to compositions and methods pertaining to PNA synthons, PNA oligomers and/or PNA/DNA Chimeras comprising a universal base.

A process for the preparation of a compound of formula (I): ##STR1## which comprises cyclization of a compound of formula (II): ##STR2##

A process is provide for the preparation of compounds of formula (I) herein ##STR1## comprising reacting a compound of formula (III), (IV) or (V) ##STR2## wherein the variables are as defined in the specification. The reaction is conducted in the presence of .sup.- OR.sup.3 and a hydroxide trapping agent or in the case of compounds of formula (IV) reacting in the presence of an auxiliary base and a hydroxide trapping agent.

A method for preparing pyrazolopyrimidinone derivatives and their pharmaceutically acceptable salts having efficacy on the treatment of impotence, one of male sexual dysfunctions. The method comprises the steps of: a) chlorosulfonating a pyrazolamide compound to obtain a chlorosulfonated compound; b) reacting the chlorosulfonated compound of step (a) with a primary amine to obtain a sulfonamide compound and c) performing an intramolecular cyclization of the sulfonamide compound of step (b) to pr...

The pyrazoles and pyzazolopyrimidines of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and A are as defined herein, have corticotropin releasing factor (CRF) antagonist activity. As such, they are effective in the treatment of a wide range of diseases including stress-related illnesses.

Sildenafil, a known pharmaceutical chemical useful in treatment of male sexual dysfunction, is prepared by processes in which the final chemical intermediate is of significantly lower basicity than sildenafil itself, so that sildenafil can be extracted in substantially pure form from the organic reaction mixture in which it is made by adding an aqueous medium of appropriately chosen acidic pH and causing phase shift of the sildenafil to occur selectively into the aqueous phase.

Compounds of the formula ##STR1## wherein R.sup.1 is H, C.sub.1 -C.sub.3 alkyl, C.sub.3 -C.sub.5 cycloalkyl or C.sub.1 -C.sub.3 perfluoroalkyl; R.sup.2 is H, C.sub.1 -C.sub.6 alkyl optionally substituted by OH, C.sub.1 -C.sub.3 alkoxy or C.sub.3 -C.sub.6 cycloalkyl, or C.sub.1 -C.sub.3 perfluoroalkyl; R.sup.3 is H, C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.1 -C.sub.6 perfluoroalkyl or (C.sub.3 -C.sub.6 cycloalkyl)C.sub.1 -C.sub...

The A21 receptor extracelluar site and the A2 receptor extracellular site of adenosine analogues are structurally different and that binding orientations of adenosine or adenosine analogues are different at these sites and this may be used to determine their structure. Novel pyrimidine compounds are described.

Novel derivatives of 1-phenyl-1H-pyrazolo[3,4-d]pyrimidine substituted at the 4-position of the pyrimidine ring are provided. A typical example is 1-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4-carbonitrile. The compounds exhibit excellent anti-carcinogenic activities as evidenced by the animal test with mice.

A polymorph of 1-{6-ethoxy-5-[3-ethyl-6,7-dihydro-2-(2-methoxyethyl)-7-oxo-2H-pyrazolo[4, 3-d]pyrimidin-5-yl]-3-pyridylsulfonyl}-4-ethylpiperazine.