反应详情

4-(2-Methoxy-ethyl)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester (8 g) was dissolved in methylene chloride (40 ml), trifluoroacetic acid (75.57 g, 50.72 ml) was added under an argon atmosphere at RT and the mixture was stirred for 2 hours until completion of the reaction. The reaction mixture was diluted with dichloromethane (500 ml), and then 3M NaOH (220.9 ml) was slowly added. The layers were separated, the organic layer washed with brine, dried over sodium sulphate and concentrated to give 4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester a brown oil (3.76 g) which was essentially pure according to NMR and used in next reaction step without further purification. MS (ESI): 216.3 (MH+).

1. customThe layers were separated
2. washthe organic layer washed with brine
3. dry with materialdried over sodium sulphate
4. concentrationconcentrated