2-Bromoethyl methyl ether → 4-(2-Methoxy-ethyl)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester

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Reaction Conditions

Reaction Steps

LDA (2M solution in THF/heptane/ethylbenzene, 24.48 ml, 0.049 mol) was added under an argon atmosphere to THF (150 ml) at −5° C., piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester (6.3 g, 6 ml) in THF (100 ml) was then added dropwise and the mixture was stirred for 2 hour at 0° C. Then 1-bromo-2-methoxy-ethane (6.8 g) was added at 0° C. and the mixture was stirred overnight at RT. The solvent was evaporated off, the residue partitioned between AcOEt and water. The layers were separated, the organic layer was washed with brine, dried over sodium sulphate and then concentrated to give 4-(2-methoxy-ethyl)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester (8 g) as a brown oil which was essentially pure and used in the next step without further purification. MS (ESI): 216.3 [(M-Boc)H+].

Provenance & Evidence