Carbamate → 2,2-Dimethoxypropane
Reaction equation
[C:1](=O)([O-:3])N.C1N=C(Cl)C2N=CN([C@@H:15]3[O:19][C@H:18]([CH2:20]O)[C@@H:17](O)[C@H]3O)C=2N=1.N[C@H]1CCCO1>>[CH2-:17][C:18]([CH3:20])=[O:19].[CH3:1][O:3][C:18]([O:19][CH3:15])([CH3:17])[CH3:20]Participants
5
Procedure
Preparation of compounds 6 and 7 starting from compound 3 is shown in the synthesis scheme below. Compound 3 was prepared from 6-chloropurineriboside 1 and 3 (R)-aminotetrahydrofuran following the procedure reported earlier (U.S. Pat. No. 5,789,416). Protection of the 2′ and 3′ hydroxy groups as an acetonide with 2,2-dimethoxypropane in the presence of TsOH(cat.) gave 4. Reaction of 4 with CDI in THF followed by treatment with 40% aq.methylamine gave carbamate 5. Deprotection of the 2′,3′ acetonide with 80% AcOH/water at 80-90 C. gave carbamate 6. Esterification of 6 with acetic anhydride in pyridine gave diester 7.
Workup
- customis shown in the synthesis scheme below
Sources & evidence
- ORD record
- ord-8b602decbd3a45758793bba8bf560053
- Source dataset
- uspto-grants-2003_06
- Patent number
- US06576620B2
Reaction notes
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