2,2-Dimethoxypropane → (RS)-4-(4-iodo-phenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of (RS)-[2-hydroxy-1-(4-iodo-phenyl)-ethyl]-carbamic acid tert-butyl ester (7.97 g) in dichloromethane (400 ml) were added sequentially 2,2-dimethoxypropane (36 ml) and p-toluenesulphonic acid monohydrate (0.75 g) and the mixture was stirred at room temperature for 18 hours. The mixture was then washed with 0.5 N aq NaOH, the phases were separated and the organic phase was dried over sodium sulphate, filtered and concentrated in vacuo to afford (RS)-4-(4-iodo-phenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (7.05 g, 89%) as a yellow solid. MS (EI): 403 (M+), 388 ([M-CH3]+), 332 ([M-CH3—C4H8]+), 288 ([M-CH3—C4H8—CO2]+), 57 ([C4H9]+).

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