N-bromobutanimide → HCID 11349499, compound

Participants

Reaction Steps

A mixture of 6-bromomethyl 8-bromoquinoline (2) and 6-dibromomethyl 8-bromoquinoline (4) (2:4=3:1 mole ratio, with about 30 wt % succinimide) was obtained by bromination of the compound 1 in the presence of NBS and was carried through the sulfonation reaction. The presence of succinimide did not affect the sulfone formation and did simplify the isolation of the bromination product. To a slurry of the above mixture (15.0 g) in 48 mL of 20% water-DMAC was added sodium methane sulfinate (6.6 g, 64.8 mmol) in one portion at room temperature. The resulting solution was aged at room temperature until 2 was consumed (about 2h, by HPLC). Then, the reaction solution was allowed to warm up to 90° C. After 4h aging, the 6-dibromomethyl 8-bromoquinoline (4) was completely converted to product 3 (by HPLC). Then, the reaction solution was allowed to cool to room temperature and ½ saturated NaHCO3/H2O solution (160 mL) was added over 1 h. The slurry was cooled to 0° C. and aged for 1 h before filtration. The wet cake was washed with a solution of 5:1 DMAC:H2O (2×20 mL) and then H2O (2×20 mL). After drying, 3 was obtained.

Provenance & Evidence