Synthesis of 25X-BOMes and 25X-NBOHs (X = H, I, Br) for pharmacological studies and as reference standards for forensic purposes

[Display omitted] •Three NBOHs (25H-, 25I- and 25B-NBOH) were synthesized with 9–38% overall yield.•Three NBOMes (25H-, 25I- and 25B-NBOMe) were synthesized with 7–33% overall yield.•The X-ray structures of 25H-, 25I- and 25B-NBOH.HCl were disclosed. An expeditious method is reported for the synthesis of three NBOHs (25H-, 25I- and 25B-NBOH; 9–38% overall yield) and three NBOMes (25H-, 25I- and 25B-NBOMe; 7–33% overall yield) from salicylaldehyde and 2-methoxyaldehyde, respectively. The X-ray structures of 25H-, 25I- and 25B-NBOH.HCl were also determined. Our approach should provide a general entry for preparing such a class of substances for pharmacological and forensic purposes.