It has been suggested that the high iron-diamine method (HID)

which is a specific stain for gastric colon metaplasia

can be used as a diagnostic method in the detection of precancer of stomachDihydrochlorides of n

n-dimethyl-m-phenylenediamine and its p-isomer in the ratio 6:1 are the main staining ingredients of HID. Using n

n-dimethylaniline as starting material for their synthesis

m- and p-nitro isomer can be obtained in onenitration step

the former is the main product while the latter as by-product

and then reduced separately to the corresponding diamines. Both resultants conformed to the desired ratio so that the synthetic route was simplified and the cost for production was reduced.The synthetic products gave reliable stains for specimens of gastric colon metaplasia and have been supplied for the use of over 20 units engaged in research on gastric cancer.