反应详情

Anilines of general formula 9m or the corresponding bromides 3m with an 2-propan-2-ol group in 5-position of the triazolopyridine (see Scheme 18) can be prepared starting from ester 51 by bromination in chloroform followed by cyclization as already described in Scheme 8 to give 2-amino-triazolopyridine 53. The ester 53 can then be treated with methyl magnesium bromide to provide the tertiary alcohol 54. Conversion of the bromide by e.g. Suzuki reaction gives aniline 9m or after Sandmeyer reaction bromide 3m. The starting material 51 is either commercially available or can be synthesized by methods known in the art, e.g for R=Me, 51 can be prepared from the corresponding bromide by reaction with trimethyl boroxine in the presence of a palladium catalyst.