Process for preparing 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-indene-3-acetic acid by reacting fluorobenzene with an acid halide, to form an indanone, reaction of the indanone with a methylthio (or methylsulfinyl) benzyl compound to form 5-fluoro-2-methyl-1-(p-methylthiobenzyl) or (p-methylsulfinylbenzyl)-indene and reacting said indene with a glyoxylic acid. This invention relates to new processes for preparing 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-indene-3-acetic acid, to intermediates thereof and processes for said intermediates.