3-Bromothiophene → 1-Piperidinecarboxylic acid, 3-(hydroxy-3-thienylmethyl)-, 1,1-dimethylethyl ester

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, 5.0 g (30.67 mmol) of 3-bromothiophene in 5 ml of tetrahydrofuran were slowly added dropwise to 24.77 ml (32.2 mmol) of isopropylmagnesium chloride/lithium chloride complex (1.3 M in tetrahydrofuran) at 5° C. After the mixture had been stirred at 5° C. for 0.5 h, 6.54 g (30.67 mmol) of tert-butyl 3-formylpiperidine-1-carboxylate were slowly added dropwise. After removal of the cold bath, the reaction mixture was stirred for a further 1 h. Conventional work-up gave 10.3 g of tert-butyl 3-(hydroxythiophen-3-ylmethyl)piperidine-1-carboxylate; HPLC/MS (M+H-tBuO)+=244 as oil (diastereomers).

Provenance & Evidence