N-bromobutanimide → tert-butyl 5-bromo-1,2,6b,9,10,10a-hexahydropyrido[4,3-b][1,4]thiazino[2,3,4-hi]indole-8(7H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

The tert-butyl 1,2,6b,9,10,10a-hexahydropyrido[4,3-b][1,4]thiazino[2,3,4-hi]indole-8(7H)-carboxylate (2.00 g, 6.02 mmol) was dissolved in anhydrous DMF (50 mL) and then cooled in an ice/acetone bath at −10° C. for 20 min. Next, N-bromosuccinimide (1.18 g, 6.62 mmol) was added in one portion. The reaction mixture was stirred for 40 min at −10° C., then poured over an ice/water mixture (300 mL). The resulting suspension was stirred at room temperature for 30 min, and extracted with diethyl ether (4×100 mL). The organic extracts were pooled together, washed with brine and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, tert-butyl 5-bromo-1,2,6b,9,10,10a-hexahydropyrido[4,3-b][1,4]thiazino[2,3,4-hi]indole-8(7H)-carboxylate was obtained as a yellow foam (2.24 g, 91%). 1H NMR (300 MHz, CDCl3) δ1.47 (s, 9H), 1.77 (m, 2H), 3.46-3.48 (m, 4H), 2.87-3.48 (m, 6H), 6.93 (s, 1H), 6.97 (s, 1H) ppm.

Provenance & Evidence