(R)-2-Methyl-CBS-oxazaborolidine → 4-(Benzyloxy)-7-[(1R)-2-bromo-1-hydroxyethyl]-1,3-benzothiazol-2(3H)-one
Reaction equation
CB1N2CCC[C@@H]2C(C2C=CC=CC=2)(C2C=CC=CC=2)O1.B.CSC.[CH2:26]([O:33][C:34]1[C:39]2[NH:40][C:41](=[O:43])[S:42][C:38]=2[C:37]([C:44](=[O:47])[CH2:45][Br:46])=[CH:36][CH:35]=1)[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1>C1(C)C=CC=CC=1.C1COCC1>[CH2:26]([O:33][C:34]1[C:39]2[NH:40][C:41](=[O:43])[S:42][C:38]=2[C:37]([C@@H:44]([OH:47])[CH2:45][Br:46])=[CH:36][CH:35]=1)[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
A solution of [(R)-tetrahyro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c] [1,3,2]-oxazaborole] (22 μl of 1M in toluene) in dry THF(1 ml) was cooled to −5° C., stirring under nitrogen. Borane-methyl sulfide complex (2M solution in THF, 11 μl) was added and stirred for 10 min at −5° C. A solution of 4-(benzyloxy)-7-(bromoacetyl)-1,3-benzothiazol-2(3H)-one (47 mg) in dry THF (1.5 ml) was added dropwise and then another 66 μl of borane-methyl sulfide complex (2M solution in THF). The reaction mixture was left for 72 h at less than 5° C. and then partitioned between 2N HCl and ethyl acetate. The organic solution was dried (MgSO4), filtered and evaporated in vacuo. The residue was purified on a 5 g silica SPE cartridge, eluting with a stepped gradient of 10% to 25% ethyl acetate-cyclohexane mixtures to give the title compound (33 mg). LCMC RT=3.19 min.
Workup
- stirringstirred for 10 min at −5° C
- custompartitioned between 2N HCl and ethyl acetate
- dry with materialThe organic solution was dried (MgSO4)
- filtrationfiltered
- customevaporated in vacuo
- customThe residue was purified on a 5 g silica SPE cartridge
- washeluting with a stepped gradient of 10% to 25% ethyl acetate-cyclohexane mixtures
Sources & evidence
- ORD record
- ord-ce280e62366e4937bcc9a4de957cd692
- Source dataset
- uspto-grants-2008_07
- Patent number
- US07402598B2
Reaction notes
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