2,2-Dimethoxypropane → 3-(2-Methoxy-1-naphthoyl)-2,2-dimethyl-1,3-oxazolidine
Reaction equation
[OH:1][CH2:2][CH2:3][NH:4][C:5]([C:7]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[CH:10]=[CH:9][C:8]=1[O:17][CH3:18])=[O:6].CO[C:21](OC)([CH3:23])[CH3:22].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CN(C)C=O>[CH3:18][O:17][C:8]1[CH:9]=[CH:10][C:11]2[C:16](=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:7]=1[C:5]([N:4]1[CH2:3][CH2:2][O:1][C:21]1([CH3:23])[CH3:22])=[O:6]Participants
Conditions
- Temperature
- 60 °C
Procedure
To a solution of Example 175A in anhydrous N,N-dimethyl formamide (10 mL) was added 2,2-dimethoxypropane (0.62 mL, 5.0 mmol) and p-toluenesulfonic acid monohydrate (50 mg, 0.26 mmol). The resulting mixture was stirred under a N2 atmosphere at 60° C. for 16 h. Additional 2,2-dimethoxypropane (0.3 mL, 2.4 mmol) and p-toluenesulfonic acid monohydrate (50 mg, 0.26 mmol) were added, and the mixture was stirred at 60° C. for 6 h. The mixture was partitioned between saturated NaHCO3 (50 mL) and ethyl acetate (3× 50 mL), and the combined organic layers were dried over Na2SO4. The crude product was purified by column chromatography on silica gel using a solvent gradient of 50-65% ethyl acetate in hexane. The title compound was obtained as a colorless, crystalline solid (0.44 g, 62% for two steps). 1H NMR (300 MHz, CDCl3) δ 1.83 (s, 3H), 1.88 (s, 3H), 3.13 (m, 1H), 3.40 (m, 1H), 3.92 (m, 2H), 3.98 (s, 3H), 7.28 (m, 1H), 7.37 (m, 1H), 7.49 (m, 1H), 7.71 (m, 1H), 7.80 (m, 1H), 7.86 (m, 1H).
Workup
- stirringthe mixture was stirred at 60° C. for 6 h
- customThe mixture was partitioned between saturated NaHCO3 (50 mL) and ethyl acetate (3× 50 mL)
- dry with materialthe combined organic layers were dried over Na2SO4
- customThe crude product was purified by column chromatography on silica gel using a solvent gradient of 50-65% ethyl acetate in hexane
Sources & evidence
- ORD record
- ord-fe4be13fa4384cb8a4daeb50af0cda1b
- Source dataset
- uspto-grants-2009_05
- Patent number
- US07538105B2
Reaction notes
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