N-bromobutanimide → 7-Bromo-2-methyl-4-benzoxazolamine

Participants

Reaction Conditions

Reaction Steps

Compound 474B (3.90 g, 26.3 mmol) was dissolved in DMF (45 mL) and cooled to −5° C. and N-bromosuccinimide (4.68 g, 26.3 mmol) was added in small portions and the reaction stirred for 5 h. The mixture was poured into 150 mL of ice water to give a cream colored solid which was filtered, washed with water, dissolved in CH2Cl2, dried over MgSO4, filtered and concentrated in vacuo. Purification of the crude material by flash chromatography on silica gel eluting with 20% ether/CH2Cl2 gave compound 474C (3.36 g, 56%) as a beige solid. HPLC: 95.4% at 2.583 min (retention time) (YMC S5 ODS column, 4.6×50 mm, eluting with 10-90% aqueous methanol over 4 min containing 0.2% phosphoric acid, 4 mL/min, monitoring at 220 nm). MS (ES): m/z 228.03 [M+H]+.

Provenance & Evidence