Abstract: The present invention is directed to compounds of formula (I), ##STR1## wherein R.sup.1 is OH, NH.sub.2 ; R.sup.2 is a heteroaromatic or aromatic substituent; R.sup.3 is H, OH, F, OCH.sub.3 ; R.sup.4 is H, F, OH or an ether or ester residue thereof, OCH.sub.3, CN, C.dbd.CH, N.sub.3 ; R.sup.5 is OH or an ether or ester residue thereof including mono, di- and triphosphate esters (.alpha.), wherein n is 0 or 1 and M is hydrogen or a pharmaceutically acceptable counterion such as sodium, potassium, ammonium or alkylammonium; and pharmaceutically acceptable salts thereof; and pharmaceutical compositions comprising said compounds can be used for therapeutic treatment of virus infections.

Abstract: The present invention is directed to a method of treating an HIV infection in a host in need of such treatment which comprises administering an effective anti-HIV amount of a compound having the formula ##STR1## wherein: R.sup.1 is hydrogen, hydroxyl;R.sup.2 is amino;R.sup.3 and R.sup.4 are independently selected from hydroxyl or an ester residue of said hydroxyl group derived from R.sup.6 COOH, wherein R.sup.6 is hydrogen, or C.sub.1 -C.sub.3 alkyl; and n is 1; or a pharmaceutically acceptable salt thereof.

Abstract: A 2',3'-deoxy-3'-fluoro-pyrimidine nucleoside having the formula: ##STR1## wherein R.sup.1 is OH or NH.sub.2 ;R.sup.2 is CF.sub.3, CH.sub.2 CH.sub.2 CH.sub.3, ##STR2## CH.sub.2 OCH.sub.3, CH.sub.2 SCH.sub.3, CH.dbd.CH.sub.2 CH.dbd.CH--CH.sub.3, C.tbd.CH, C.tbd.C--CH.sub.3 or CH.sub.2 --C.tbd.CH;or a pharmaceutically acceptable salt thereof.These nucleoside analogs exhibit antiviral activity against HIV.

Abstract: Use of a compound of the formula ##STR1## wherein Base is thymine, Cytosine, adenine or guanine, or a physiologically acceptable salt thereof, for therapeutic treatment of hepatitis B virus infections and to a method for such treatment.

Abstract: A compound of the formula ##STR1## wherein the radicals A, X, R.sup.1, R.sup.2 and R.sup.3 are defined as follows:A: ##STR2## X: (a) O (b) S(c) CH.sub.2R.sup.1 : H; alkyl containing 1-3 carbon atoms;--CH.dbd.CH.sub.2 ; --CH.dbd.CH--CH.sub.3 ; --CH.sub.2 --CH.dbd.CH.sub.2 ; ##STR3## --C.tbd.CH p1 R.sup.2 : H; or R.sup.2 constitutes together with R.sup.3 a carbon--carbon bondR.sup.3 : H; F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 ; CH.sub.2 OH; and when R.sup.3 is F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 or CH.sub.2 OH it may have either the cis-configuration or trans-configuration relative to the hydroxymetyl function at position 4', or R.sup.3 constitutes together with R.sup.2 a carbon--carbon bond, and therapeutically acceptable salts thereof, for use in therapy, in particular for the treatment of HIV virus infections.

Abstract: Antivirally active compounds of formula (I), wherein R.sup.1 is hydrogen, hydroxy, mercapto or amino; R.sup.2 is hydrogen, hydroxy, fluoro, chloro or amino; R.sup.3 and R.sup.4 are independently selected from (II), (III), amino, hydroxy or an ether or ester residue thereof, or R.sup.3 together with R.sup.4 is (IV), wherein M is hydrogen or a pharmaceutically acceptable counterion; and n is 1 or 2; with the proviso that, when R.sup.2 is amino and R.sup.3 and R.sup.4 are hydroxy R.sup.1 is not hydroxy and in addition, when n=1, R.sup.1 is not hydrogen, and pharmaceutically acceptable salts thereof; processes for preparation of said compounds, a pharmaceutical composition comprising said compounds, methods for treatments of virus infections as well as use of compounds of formula (I) without the proviso for the manufacture of a medicament for treatment of AIDS.

Abstract: A compound of the formula ##STR1## wherein the radicals A, X, R.sup.1, R.sup.2 and R.sup.3 are defined as follows: ##STR2## R.sup.2 : H; or R.sup.2 constitutes together with R.sup.3 with a carbon - carbon bondR.sup.3 : H; F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 ; CH.sub.2 OH; and when R.sup.3 is F; Cl; Br; I; N.sub.3 ; CN; C.tbd.CH; OH; OCH.sub.3 or CH.sub.2 OH it may have either the cis-configuration or trans-configuration relative to the hydroxymethyl function at position 4', or R.sup.3 constitutes together with R.sup.2 a carbon - carbon bond, and therapeutically acceptable salts thereof, for use in therapy, in particular for the treatment of HIV infections.

Abstract: Use of a compound of the formula ##STR1## wherein A is .beta.-2'-deoxy-D-ribofuranosyl or .beta.-D-arabinofuranosyl;R.sup.1 is hydroxy or amino;R.sup.2 is cycloalkyl or alkyl-substituted cycloalkyl containing 1-5 carbon atoms; saturated or unsaturated, straight or branched alkyl containing 1-5 carbon atoms which may be unsubstituted or substituted with halogen, hydroxy, mercapto, trifluoroalkyl or difluoroalkyl containing 1-3 carbon atoms, phenoxy or alkoxy containing 1-3 carbon atoms; phenyl or phenylalkyl containing 1-3 carbon atoms in the alkyl part, or a physiologically acceptable salt thereof,for manufacture of a medicament for therapeutic or prophylactic control or treatment of retrovirus, especially HIV, or hepatitis B virus infections in animal and man and to a method of such treatment.

Abstract: Antivirally active compounds of the formula ##STR1## wherein R.sub.1 is hydrogen or hydroxymethyl;R.sub.2 is hydrogen, hydroxy or hydroxymethyl;R.sub.3 is hydrogen; or R.sub.1 and R.sub.3 together constitute an additional carbon-carbon bond;with the proviso that when R.sub.1 is hydrogen then R.sub.2 is hydroxy or hydroxymethyl, that when R.sub.1 is hydroxymethyl then R.sub.2 is hydrogen and that when R.sub.2 is hydroxy then R.sub.1 is hydrogen; and physiologically acceptable salts; geometric or optical isomers thereof; processes for preparation of said compounds, pharmaceutical preparations containing the compounds, methods for treatment of virus infections and medical use of the compounds.

Abstract: A compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different, and each is selected from the group consisting of hydrogen and phenyl groups of the formula ##STR2## wherein R.sub.4 and R.sub.5 are the same or different and each is selected from the group consisting of hydrogen, halogen, alkyl having 1, 2, or 3 carbon atoms, alkoxy having 1, 2, or 3 carbon atoms, alkoxycarbonyl having 2-7 carbon atoms; and alkylcarbonyl groups having 2-7 carbon atoms; or R.sub.4 and R.sub.5 together form a straight saturated alkylene chain having 3 or 4 carbon atoms and being bound to adjacent positions, i.e. 2,3- or 3,4- in the phenyl ring; provided that one of R.sub.1 and R.sub.2 is a phenyl group of the formula II when R.sub.3 is H; and physiologically acceptable salts and optical isomers thereof; methods for preparation of the compounds, pharmaceutical compositions containing them, and their medicinal use.