Processes for producing indole compound

A process for producing an indole compound represented by the formula (2) which comprises reducing a 2-nitrobenzylcarbonyl compound represented by the formula (1) (wherein R1 and R2 each independently represents hydrogen or optionally substituted alkyl or phenyl; R3 represents alkyl, halogeno, etc.; and n is an integer of 0 to 4) with a hydrogen donor in the presence of a reduction catalyst, characterized in that an acylating agent and a base are caused to coexist in the reduction step; the process in which the 4-fluoro-2-nitrophenylacetone produced from 2-chloro-4-fluoronitrobenzene is used; and a process for producing a sulfamoyltriazole compound which comprises reacting the indole compound with 1-(N,N-dimethylsulfamoyl)-3-chlorosulfonyl-1,2,4-triazole.