Silylated-pyrimidine prodrugs, compositions that include the silylated-pyrimidine prodrugs, methods for making the silylated-pyrimidine prodrugs and compositions, and methods for treating cancer using the silylated-pyrimidine prodrugs and compositions.

Silylated-pyrimidine prodrugs, compositions that include the silylated-pyrimidine prodrugs, methods for making the silylated-pyrimidine prodrugs and compositions, and methods for treating cancer using the silylated-pyrimidine prodrugs and compositions.

The present invention relates to a prodrug of 5-azacytidine or 2′-deoxy-5-azacytidine having remarkable stability against cytidine deaminase, a metabolic hydrolyzing enzyme in replacement of current injections (5-azacytidine or 2′-deoxy-5-azacytidine) which are clinically used as therapeutic agents for various myelomas including myelodysplastic syndrome. The present invention provides a compound represented by formula (1), or salt thereof,

##STR00001## wherein, R is OR.sup.3 or a hydrogen atom, R.sup.1, R.sup.2, and R.sup.3 are each independently hydrogen atom or silyl group represented by formula (2):

##STR00002## wherein, R.sup.1, R.sup.5, and R.sup.6 are each independently alkyl group which may have a substituent, aryl group which may have a substituent, or arylalkyl group which may have a substituent, with the provision that R.sup.1, R.sup.2, and R.sup.3 are not hydrogen atom simultaneously.

Disclosed are halogenated 2-deoxy-lactone, 2′-deoxy-nucleosides, and derivatives thereof, for example, a compound of formula (I). Also disclosed are a composition comprising a pharmaceutically acceptable carrier and at least one compound or salt of the invention, and a method of treating a disorder is selected from the group consisting of an abnormal cellular proliferation, a viral infection, and an autoimmune disorder. ##STR00001##

Disclosed are halogenated 2-deoxy-lactone, 2′-deoxy-nucleosides, and derivatives thereof, for example, a compound of formula (I). Also disclosed are a composition comprising a pharmaceutically acceptable carrier and at least one compound or salt of the invention, and a method of treating a disorder is selected from the group consisting of an abnormal cellular proliferation, a viral infection, and an autoimmune disorder. ##STR00001##

The present invention is directed to 4′-substituted nucleoside derivatives of Formula I ##STR00001##
and their use in the inhibition of HIV reverse transcriptase, the prophylaxis of infection by HIV, the treatment of infection by HIV, and the prophylaxis, treatment, and delay in the onset or progression of AIDS and/or ARC.

The present invention is directed to 4′-substituted nucleoside derivatives of Formula I ##STR00001##
and their use in the inhibition of HIV reverse transcriptase, the prophylaxis of infection by HIV, the treatment of infection by HIV, and the prophylaxis, treatment, and delay in the onset or progression of AIDS and/or ARC.

Halogenated analogs of 5-aza-2′-deoxycytidine, such as halogenated analogs of 5-aza-4′-thio-2′-deoxycytidine (5-aza-T-dCyd) are described. Pharmaceutical compositions including a halogenated analog and methods of using the halogenated analogs to inhibit neoplasia are described. In some examples, the halogenated analogs have a structure according to formula Ia, or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:

##STR00001##

The present invention relates to polymorphic forms of 5-Azacytidine and the process for preparation thereof. The present invention further relates to Crystalline 5-azacytidine 5 designated as Form-SA-1 characterized by an X-ray powder diffraction pattern having at least four characteristic diffraction angle peaks at about 12.00, 12.60, 13.90, 15.15 and 31.40±0.20 2θ°, which is useful as active pharmaceutical ingredient in pharmaceutical compositions for the treatment of myelodysplastic syndrome.

The present invention relates to polymorphic forms of 5-Azacytidine and the process for preparation thereof. The present invention further relates to Crystalline 5-azacytidine 5 designated as Form-SA-1 characterized by an X-ray powder diffraction pattern having at least four characteristic diffraction angle peaks at about 12.00, 12.60, 13.90, 15.15 and 31.40±0.20 2θ°, which is useful as active pharmaceutical ingredient in pharmaceutical compositions for the treatment of myelodysplastic syndrome.