Abstract
Nucleophilic substitution of the 5‐bromo group in 1 by methyl 3‐mercaptopropionate gave the 5‐alkyl‐mercapto derivative 2. Reduction of 2 with H2/Pd led to the amine 3, meanwhile reduction with Fe/HOAc afforded the 5‐acetamido derivative 4 and not the cyclized derivative 1,3,8‐triaza‐azulen‐7‐one 6, as expected. Treatment of 3 with NaOMe/MeOH furnished the racemic mixture 5a and 5b via an unexpected reactivity.
Acknowledgment
We thank U. Beifuß, Fakultät für Chemie at the Universität Hohenheim, Germany, for assisting in the NMR experiment and mass spectra measurements.