From the above observations we found that inclusion of TBHP or atmospheric O
aromatization process.Therefore, we conclude that the aromatization of tetrahydrocarbazole can be achieved without using
TBHP or atmospheric O in an excellent yield.
2
has no any significant role in the
2
Based on the literature as well as experimental precedents we carried, copper (II) chloride dihydrate has unusual strong
tendency to form dimethyl sulphoxide complex or CuCl .2DMSO solvates, which is presumably driving force for this
On further increasing the temperature promotes the copper dissolution reaction to
2
1
2a-c
unique aromatization reaction.
generate CuCl as the self-catalytic intermediate species in DMSO. This self-catalytic intermediate species (CuCl) is key
factor responsible for the aromatization reaction to proceed smoothly.
2 2
Conclusion: In summary, we have successfully developed catalytic CuCl .2H O in DMSO as an aromatization protocol
for tetrahydrocarbazole. we have efficiently utilize this protocol, for the synthesis 32 compounds including substituted
carbazoles, bioactive carbazole alkaloids such as 3-methylcarbazole 2a, glycozoline 2p, glycozolicine 2q, 3-formyl
carbazole 3 and clauszoline-K 5, N- substituted carbazole 7a-d, quinoline 9, isoquinoline 11 and β-carboline 13 in
excellent yield. The present methodology is operationally simple and does not require expensive reagent. It accepts
approximately all electron neutral (2c-f), rich (2a, 2j-u) and deficient substrates (2h, 2i, 2v) in benzene ring of
1
3a-d
tetrahydrocarbazole. In addition, considering the importance of its impurity biscarbazole,
our future studies will be
focused on the development of methodology for the synthesis of biscarbazole obtained during optimization of
aromatization reaction.
Acknowledgement
B.D.A is grateful to UPE fellowship, SPPU Pune.
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