Trityl chloride → 6-Bromo-3-trityl-3H-benzooxazol-2-one
Reaction equation
[Br:1][C:2]1[CH:11]=[CH:10][C:5]2[NH:6][C:7](=[O:9])[O:8][C:4]=2[CH:3]=1.C(N(CC)CC)C.[C:19](Cl)([C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.CCOC(C)=O>C(Cl)Cl>[Br:1][C:2]1[CH:11]=[CH:10][C:5]2[N:6]([C:19]([C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)([C:32]3[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=3)[C:26]3[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=3)[C:7](=[O:9])[O:8][C:4]=2[CH:3]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 6-bromo-3H-benzoxazol-2-one (15 g; ca. 0.07 mol, containing 8-9% 3H-benzooxazol-2-one) and triethylamine (11.1 mL, 0.08 mol) in DCM (250 mL) was added trityl chloride (21.5 g, 0.08 mol). The solution was stirred at room temperature for 18 h and was then washed with distilled water (3×250 mL), brine (250 mL) and dried (MgSO4), filtered and evaporated to give an off-white colored solid. The product was dissolved in refluxing EtOAc then allowed to cool to room temperature with constant stirring for several hours. The solids were collected (21.16 g) and the filtrate was concentrated until precipitation occurred, re-heated (reflux) for several hours and allowed to cool with stirring to encourage a second crystallization (7.88 g).
Workup
- washwas then washed with distilled water (3×250 mL), brine (250 mL)
- dry with materialdried (MgSO4)
- filtrationfiltered
- customevaporated
- customto give an off-white colored solid
- dissolutionThe product was dissolved
- temperatureto cool to room temperature
- stirringwith constant stirring for several hours
- customThe solids were collected (21.16 g)
- concentrationthe filtrate was concentrated until precipitation
- temperaturere-heated
- temperature(reflux) for several hours
- temperatureto cool
- stirringwith stirring
- customa second crystallization (7.88 g)
Sources & evidence
- ORD record
- ord-803e9630e1164f829161b530594885da
- Source dataset
- uspto-grants-2009_12
- Patent number
- US07625889B2
Reaction notes
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