Adenosine benzoylation

Ap4A, diadenosine tetraphosphate BBG, Brilliant blue green BzATP, 2 - 3 -0-(4-benzoyl-benzoyl)-ATP cAMP, cyclic AMP CCPA, chlorocyclopentyl adenosine CPA, cyclopentyl adenosine CTP, cytosine triphosphate DPCPX, 8-cyclopentyl-1,3-dipnopylxanthine IP3, inosine triphosphate lpsl, diinosine penta phosphate a,p-meATP, a,p-methylene ATP p.y-meATP, p.y-meihylene ATP 2-MeSADP, 2-methylthio ADP 2-MeSAMP, 2-methylthio AMP 2-MeSATP, 2-methylthio ATP NECA, 5 -W-ethylcarboxamido adenosine PPADS, pyridoxal-phosphate-6-azophenyl-2, 4 -disulfonic acid PLC, phospholipase C RB2, reactive blue 2 TNP-ATP, 2, 3 -0-(2,4,6-trinitrophenyl) ATP. 

Abbreviations ADA, adenosine deaminse BAEE, N,a-benzoyl-L-arginine ethyl ester, BTEE, N,oc-benzoyl-L-tyrosine ethyl ester BTNA, N,a-benzoyl-L-tyrosine-p-nitroanilide ZAPA, N,a-benzoylcarbonyl-L-arginine-p-nitroanilide. 

Zur selektiven Entfernung von N-Benzoyl-Gruppen bei Vorhandensein von O-Benzoyl-Gruppen, z. B. in der Nukleosid-Chemie, laBt sich die Kombination Bortrifluorid/Zink-bromid verwenden, wie nachstehend fur die N-Debenzoylierung von 3, 5 -0,0,NH-Tri-benzoyl-2 -deoxy-adenosin zu 3, 3 -0,0-Dibenzoyl-2 -deoxy-adenosin (93%) formuliert3 ... 

For example, N-4 of cytosine and N-6 of adenosine may carry benzoyl groups. The 5 - OH of each nucleotide is blocked by a di-p-anisylphenylphenylmethyl (also called dimethoxytrityl, DMTO) group. The 3 -OH is converted to one of a number of activated derivatives such as the following N, N-diisopropylamino phosphines.575 577-579... 

Similarly the dixanthate olefin synthesis, which works well with tin hydride, can also be performed with Ph2SiH2.19 Reduction of dixanthate 24 (B = adenosine) in refluxing toluene afforded 25 (B = adenosine) in 95 % yield. Initiation was by AIBN or benzoyl peroxide. 

Cytidin- -dimethylester XII/2, 272 Cytidin-5 - -morpholid XII/2, 402 Cytidin- -propylester XII/2, 272 -decylamid-dichlorid XII/2, 385 -decylamid-diphenylester XII/2, 435 -decylester XII/2, 179 E2, 500, 561 -decylester-dichlorid XII/2, 213f. Desoxy-adenosin-5 - XII/2, 207 Desoxy-cytidin-3 - XII/2, 180 Desoxy-cytidin-5 - -morpholid XII/2, 402 2-Desoxy-3,4-di-0-benzoyl-D-ribose-dimethyl-acetal-5- -diphenylester XII/2, 194 -6-(desoxy-D-gluconsaureester) XII/2, 209 2-Desoxy-D-glucose-6- XII/2, 194... 

Adenosine (131) Acetal MeOH EtjN Amb. Benzoyl chloride 2 0 3 70 — 1... 

The adenosine analog containing an imidazo[4,5-c]pyridazine (252) has been prepared by the condensation of (249) with 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide (250) to produce (251). Removal of the benzoyl groups is readily achieved by methanolic ammonia at room temperature, and then the chlorine is displaced with ethanolic ammonia in an autoclave at high temperatures to afford (252) (74JHC39). 

Nucleosides relating to adenosine have been made by condensation of an imidazo[4,5-d]pyridazine with a blocked carbohydrate. The chloromercury derivative of 4(7)-benzoyl-aminoimidazo[4,5-condensed with 2,3,5-tri-O-benzoyl-D-ribofuranosyl chloride to give a mixture of nucleosides. After removal of the blocking groups and separation, the products were identified as (255e) and (2551) <57JOC954). 

The introduction by Davoll and Lowy of the chloromercurio derivatives of purines, in place of the silver salts, represents a significant improvement in technique. Adenosine (1) and guanosine (2) were obtained in sufficient yield via 5 and 6, respectively. The introduction of 2,3,5-tri-(2-benzoyl-D-ribofuranosyl chloride even increased the glycosylation yields.The heavy-metal salts are usually insoluble in hydrocabons. Therefore, the Fischer-Helferich-Davoll-Lowy condensation is a heterogeneous reaction. 

The solubility of purines in the required apolar solvents was, at first, a problem for this method. By using long alkyl chain derivatives of the appropriate purine base, 7V-glycosylation has been accomplished in the presence of a Lewis add. An example is the synthesis of adenosine via 2, 3, 5 -tri-(7-benzoyl-A -octanoyladcnosine (15). ... 

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