N-bromobutanimide → Methyl 2-amino-4,5,6,7-tetrahydro-1,3-benzothiazole-6-carboxylate

Participants

Reaction Steps

The procedure of M. E. Jung, et al, Journal of the American Chemical Society, Volume 103, pages 6177-6185 (1981), is followed to prepare (±)-methyl 4-[(trimethylsilyl)oxy]-3-cyclohexene-1-carboxylate. A solution of 100 g of this compound in 500 ml of dry tetrahydrofuran is cooled in an ice bath under nitrogen and treated sequentially with N-bromosuccinimide (92.91 g) and 20 minutes later with thiourea (39.73 g). The mixture is refluxed under nitrogen for two hours. The solvent is removed in vacuo and the residue is partitioned between chloroform and a dilute solution of ammonium hydroxide. The organic phase is washed with brine and dried over magnesium sulfate. Evaporation of the solvent gives 82.7 g of the title compound; mp 148°-168° C.

Provenance & Evidence