Dimethylformamide → HCID 23585448, compound

Participants

Reaction Steps

4-Bromoindazole of Example 2 (17.4 g, 0.088 M), benzyl bromide (22.7 g, 0.132 M) and DMF (35 mL) were heated to about 50° C. for 25 hours (HPLC: 15:1 ratio of 2-N and 1-N isomers). The mixture was cooled to ambient temperature and diluted with ethyl acetate (160 mL) and water (100 mL). The organic layer was separated, washed with aqueous sodium bicarbonate (5%, 100 mL). The organic layer was separated and concentrated under reduced pressure. The residue was diluted with isopropanol (160 mL) and concentrated under reduced pressure to a volume of about 120 mL. The mixture was heated to 50° C. to dissolve the solid and diluted with water (70 mL) to precipitate the product. The slurry was cooled to 0° C. and the precipitate was filtered off. The solid was washed with a mixture of IPA and Water (1:1, 50 mL), and dried at 50° C. to provide the titled compound (16.5 g, 77%, which contained less than 2% of 1-N-isomer by HPLC): 1H NMR (CDCl3, δ, ppm) 5.56 (s, 2H), 7.11 (m, 1H), 7.21 (d, J=7.2 Hz, 1H), 7.24-7.39 (m, 5H), 7.65 (d, J=8.6 Hz, 1H), 7.88 (s, 1H).

Provenance & Evidence