Phosphorus sulfide (P2S5) → (2R,3S,4R,5R)-2-(hydroxymethyl)-5-(6-sulfanylpurin-9-yl)oxolane-3,4-diol
Reaktionsgleichung
[C@@H:1]1([N:10]2[C:19]3[N:18]=[CH:17][N:16]=[C:14](N)[C:13]=3[N:12]=[CH:11]2)[O:9][C@H:6]([CH2:7][OH:8])[C@@H:4]([OH:5])[C@H:2]1[OH:3].N(O)=O.C(OC(=O)C)(=O)C.CN(C)C1C=CN=CC=1.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:40]>>[C@@H:1]1([N:10]2[C:19]3[N:18]=[CH:17][N:16]=[C:14]([SH:40])[C:13]=3[N:12]=[CH:11]2)[O:9][C@H:6]([CH2:7][OH:8])[C@@H:4]([OH:5])[C@H:2]1[OH:3]Komponenten
5
Versuchsvorschrift
Concomitant hydrolysis of the nitrile function and the sugar protecting groups of compound 41 is carried out by the treatment with 0.1N NaOH solution to obtain 4-amino-3-(β-D-ribofuranosyl)-1,3-azaphospholine-5-carboxamide (compound 50). Compound 50 is ring closed with formamide or with triethyl orthoformate to obtain the inosine analog, compound S1 (X=O), which is also prepared by deamination of the adenosine analog, compound 44, with aqueous nitrous acid. Acetylation of the sugar hydroxyls with acetic anhydride/4-(dimethylamino)pyridine, followed by thiation with phosphorus pentasulfide and subsequent deacetylation provides the 6-thioinosine analog 3-(β-D-ribofuranosyl)-1,3-azaphospholo[4,5-d]pyrimidine-7(6H)-thione (compound 51, X=S).