Abstract: A process for the preparation of a compound of formula (I) comprising the steps: (a) reacting a compound of formula (II) ?wherein L and L? are suitable leaving groups, with a compound of formula (III) UNH2??(III) to prepare a compound of formula (IV) and subsequently (b) substituting the group R1 by replacement of the leaving group L?.

Abstract: The invention provides a process for manufacturing at low cost cellulose acetate, which is useful as a biodegradable plastic, using corncob meal which has hitherto been thrown away as a raw material. More specifically, the invention provides a process for manufacturing cellulose acetate, which comprises the steps of: steaming corncob meal at a temperature of 150 to 250° C. and a pressure of 20 to 29 MPa; filtering the steamed corncob meal to obtain a solid product; and dehydrating and acetylating by adding acetic anhydride and sulfuric acid to the solid product. The steaming is preferably carried out by using a pressure vessel and the filtering is preferably carried out by using a filtering device.

Abstract: This invention relates to a starch based tablet disintegrant useful at low addition levels and providing equally effective properties in water and physiological fluids. The starches are characterized by their low solubility in cold water, high swelling power and labile birefringence in the dry state, which rapidly disappears upon addition of water. The preferred starches are inhibited then processed to remove a portion of the granular structure.

Abstract: Sequence-specific oligonucleotides are provided having substantially pure chiral Sp phosphorothioate, chiral Rp phosphorothioate, chiral Sp alkylphosphonate, chiral Rp alkylphosphonate, chiral Sp phosphoamidate, chiral Rp phosphoamidate, chiral Sp phosphotriester, and chiral Rp phosphotriester linkages. The novel oligonucleotides are prepared via a stereospecific SN2 nucleophilic attack of a phosphodiester, phosphorothioate, phosphoramidate, phosphotriester or alkylphosphonate anion on the 3′ position of a xylonucleotide. The reaction proceeds via inversion at the 3′ position of the xylo reactant species, resulting in the incorporation of phosphodiester, phosphorothioate, phosphoramidate, phosphotriester or alkylphosphonate linked ribofuranosyl sugar moieties into the oligonucleotide.

Abstract: A method and composition for the treatment of HIV and HBV infections in humans and other host animals is disclosed that includes the administration of an effective amount of a [5-carboxamido or 5-fluoro]-2′,3′-dideoxy-2′,3′-didehydro-pyrimidine nucleoside or a [5-carboxamido or 5-fluoro]-3′-modified-pyrimidine nucleoside, or a mixture or a pharmaceutically acceptable derivative thereof, including a 5′ or N4 alkylated or acrylated derivative, or a pharmaceutically acceptable salt thereof, in a pharmaceutically acceptable carrier.

Abstract: The present invention provides a novel purine 4'-thioarabinonucleoside represented by the following formula ?1!: ##STR1## wherein B represents a purine base other than adenine. Also disclosed are a method for preparing the purine 4'-thioarabinonucleoside and pharmaceutical compositions containing the purine 4'-thioarabinonucleoside.

Abstract: Ether variant lipids bound to phosphoramidites are disclosed. These can be used to create oligonucleotides that are linked to stable lipid-like units. For example, dialkyl glycerols are linked to phosphoramidites.

Abstract: The present invention relates to novel ribonucleotide reductase inhibitors and new combinations comprising an antiviral compound, such as acyclovir, and a thiocarbonohydrazone ribonucleotide reductase inhibitor for the chemotherapeutic treatment of virus infections, especially viruses of the herpes group.

Abstract: Compounds of the formula ##STR1## and the nontoxic pharmaceutically acceptable salt thereof, wherein D is the residue of a centrally acting drug containing at least one reactive functional group selected from the group consisting of amino, hydroxyl, mercapto, carboxyl, amide and imide, said residue being characterized by the absence of a hydrogen atom from at least one of said reactive functional groups in said drug; n is a positive integer equal to the number of said functional groups from which a hydrogen atom is absent; and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine.revreaction.pyridinium salt redox carrier, said carrier comprising a bivalent radical of the formula ##STR2## wherein the alkylene group can be straight or branched and can contain 1 to 3 carbon atoms; R.sub.

Abstract: A process is provided in which a mixture of alpha- and beta-anomers is converted selectively to the desired beta-thymidine. The process involves the following steps: (a) converting a mixture of alpha- and beta-anomers of tetra-O-acylribofuranose to tri-O-acyl-.beta.-ribothymidine; (b) converting tri-O-acyl-.beta.-ribothymidine to .beta.-ribothymidine; (c) converting .beta.-ribothymidine to 2,2'-anhydro-.beta.-thymidine; (d) converting 2,2'-anhydro-.beta.-thymidine to 2'-halo-2'-deoxy-5-methyluridine; and (e) converting 2'-halo-2'-deoxy-5-methyluridine to beta-thymidine. The mixture of alpha- and beta-anomers of tetra-O-acylribofuranose may be produced by any suitable procedure such as by converting lower alkyl ribofuranoside to the tetra-O-acylribofuranose mixture. The lower alkyl ribofuranosides may in turn be produced by various methods. However, a desirable way of effecting this conversion involves use of D-ribose as the starting material which is converted to the lower alkyl ribofuranoside.