An unusually simple procedure for the synthesis of canthin-alkaloid derivatives using dialkyl oxalates as new regioselective N-alkylating agents
✍ Scribed by Ilona Matus; János Fischer
- Book ID
- 104233266
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- French
- Weight
- 183 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
1-Alkyl-B-carbolines were treated with dialkyl oxalates to give N-alkylated canthin-alkaloid derivatives in one step During the reproduction of the experiments described by Atta-ur-Rahman 1)
we found that the reaction of 1-alkyl-8-carbolines (1) with excess dialkyl oxalates (2) between 155-175'C for 8-12 hours did not afford the pyrrolizine derivatives described by the authors. However, canthin-alkaloid derivatives (3) were formed in one step with yields between 20-65 %.
Compounds 2 have yellow colour and a green fluorescence under uv-lamp (254 and 366 nm). Products and reaction conditions are summarized in Table 1.
Only in the case of dimethyl oxalate we could not get any product. We suggest the following mechanism for the formation of N-alkylated 3H-5,6-dihydro-5,6dioxo-indolo [3,2,1-de] [1,51 -naphthyridines (3):