Alpha-azidocinnamate

To a solution of 1.84 g Na metal in 60 ml ethanol at 5-10° add, over Vi hour with vigorous stirring a mixture of 0.08 M ethyl azidoacetate and 0.02 M 2 (or 2,5 2,3 etc. but not 6) substituted benzaldehyde and continue stirring at 5-10° until nitrogen evolution ceases (about V2-I hour) then stop immediately and rapidly evaporate in vacuum Vi the ethanol (keep temperature below 30°). Basify the solution with solid NH CI, dilute with 500 ml water and extract 3 times with ether. Filter, wash with water to neutrality and dry, evaporate in vacuum the ether (or can dissolve the residue in petroleum ether, or 1 1 petroleum ether.benzene for methoxy compounds, and filter through silica gel) to get the ethyl-alpha-azidocinnamates (1) in about 50% yield. Store in freezer until used in next step. Dissolve 1 g (I) in 100 ml p-xylol and reflux 10 minutes. Evaporate in vacuum (or add 5 ml pentane, filter, evaporate in vacuum) to get about 90% yield of the 4 substituted-2-car-bethoxyindole which can be decarboxylated as described elsewhere here. 

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See also in sourсe #XX -- [ ]

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