Dexamethasone → Deltasol

Reaction equation

[CH3:1][C@H:2]1[C@:19]([OH:24])([C:20]([CH2:22][OH:23])=[O:21])[C@:18]2([CH3:25])[C@H:4]([C@H:5]3[C@:15]([F:27])([C@@H:16]([OH:26])[CH2:17]2)[C@:14]2([CH3:28])[C:8](=[CH:9][C:10]([CH:12]=[CH:13]2)=[O:11])[CH2:7][CH2:6]3)[CH2:3]1.[C:29]1(=[O:35])[O:34][C:32](=[O:33])[CH2:31][CH2:30]1>N1C=CC=CC=1.CN(C1C=CN=CC=1)C>[CH3:1][C@H:2]1[C@:19]([OH:24])([C:20]([CH2:22][O:23][C:29]([CH2:30][CH2:31][C:32]([OH:34])=[O:33])=[O:35])=[O:21])[C@:18]2([CH3:25])[C@H:4]([C@H:5]3[C@:15]([F:27])([C@@H:16]([OH:26])[CH2:17]2)[C@:14]2([CH3:28])[C:8](=[CH:9][C:10]([CH:12]=[CH:13]2)=[O:11])[CH2:7][CH2:6]3)[CH2:3]1

Participants

Procedure

An amount equivalent to 0.030 g of dexamethasone (1, 0.076 mmol, 1.0 equiv.) was completely dissolved in 1 mL of pyridine (non-anhydrous) and 0.038 g of succinic anhydride (0.382 mmol, 5.0 equiv.) was added to the clear solution. Then 1-2 mg of DMAP (7.6 μmol, 0.1 equiv.) was added to the solution and reaction was allowed to run for 48 h at r.t. under N2-flow. After 48 h, pyridine was evaporated under reduced pressure (in a rotary evaporator). A volume equivalent to 10 mL of H2O was added to the evaporated residue. A white precipitate was observed which was stirred for 10 minutes and then centrifuged. The resulting precipitate was washed again with 10 mL of H2O and the washed residue was lyophilized to yield the target product (2).