FOERFARANDE FOER FRAMSTAELLNING AV 3,5-DIAMINO-1,2,4-TRIAZOLDERIVAT

There is disclosed a process for the preparation of compounds of the general Formula I wherein R and R are independently hydrogen, alkyl, alkenyl, aralkyl or cycloalkyl; or R1 and R2, together with the adjacent nitrogen atom they are attached to, may form a heterocyclic ring; and R3 is hydrogen or alkyl and pharmaceutically acceptable acid addition salts thereof, which comprises reacting a halogen compound of the general Formula III [wherein X is halogen, which may be prepared from the hydroxy compound of general formula II, with an alkali metal of alkaline earth metal salt of a phenol derivatives of the general Formula IV and, if desired, converting the compound of general Formula I thus obtained into a pharmaceutically acceptable acid addition salt thereof. The compounds of general Formula I have a useful sustained histamine H2 blocking effect. The advantages of the process invention are that it requires readily available starting materials, provides high yields and is readily feasible on an industrial scale.