CH498136A - Pharmaceutical furazan derivs prodn - Google Patents

Abstract

Pharmaceutical furazan derivs. prodn. Cpds. possessing depressant, anticonvulsive and muscle relaxing properties have formula: (in which R1 is H or lower alkyl, and R2 is a lower alkyl in the m- or o-position). These compounds are produced by the Hoffmann reaction from the compound.

Description

  

  
 



  Process for the preparation of new furazan derivatives
The invention relates to a process for the preparation of new furazan derivatives.



   Compounds of general formula I,
EMI1.1
 in which Rt is hydrogen or a lower alkyl group and R2 is a lower alkyl group which is in the o- or m-position, have not yet become known.



   As has now been found, these compounds have valuable pharmacological properties. They have a central damping, anticonvulsant and muscle relaxant effect.



     The new compounds of general formula I can be used to calm weak states of excitement and to relieve muscle stiffness, e.g. B. in rheumatic diseases, fibrositis, bursitis, myositis, spondylitis, discopathies and torticollis can be used.



   In the compounds of general formula I, R1 and R2 as lower alkyl groups can, for example, be methyl, ethyl> propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl or the 2 , 2-Iiimethyipropyigruppen, Rt can occupy the o-, m- or p-position.



   Compounds of general formula I are obtained by adding a compound of general formula II,
EMI1.2
 in which R1 and R2 have the meaning given under formula I, degrades to the amino compound of general formula I, according to the method of Hoffmann. The starting amide of the general formula II can be obtained in a simple manner by treating the carboxylic acid of the general formula III
EMI1.3
 in which Rt and R2 have the meaning given under formula I with thionyl chloride or bromide, respectively. Phosphoryl chloride or bromide, and reaction of the resulting acid chloride with ammonia.



   The new active ingredients can be administered orally, rectally or parenterally. The daily doses range between 50-6000 mg.



   The following example explains the preparation of the new compounds of the general formula I and of intermediates not previously described, but is not intended to limit the scope of the invention in any way. The temperatures are given in degrees Celsius.



   example
A solution of 0.4 g of 4- (o-tolyl) furazan-3-ylcarboxamide in 2 ml of methanol is mixed with a solution of 80 ml of sodium hydroxide in 2.95 ml of 60% sodium hypochlorite solution in water. The mixture is kept at a bath temperature of 78-800 ° C. for 3 hours, then a solution of 0.26 g of sodium hydroxide in 0.25 ml of water is added and the mixture is refluxed for 7 hours. After cooling, the methanol is evaporated off and the residue is partitioned between water and methylene chloride. The organic phase is dried and evaporated. The crystalline residue is recrystallized from benzene-cyclohexane and gives the pure 3-amino-4- (o-tolyl) -furazan with a melting point of 86890. The 3-amino-4- (3,4-xylyl) -furazan prepared analogously melts at 111-113.

 

   The 4- (o-tolyl) furazan-3-yl-carboxamide required as the starting product is prepared as follows: a) 1.5 g of 4- (o-tolyl) -furazan-3-yl acid chloride are dissolved in 30 ml of chloroform and a stream of ammonia gas was added for 3/4 hours while cooling with ice. The suspension is diluted with water and the chloroform phase is separated off, washed with water, dried and evaporated. The residue is recrystallized from chloroform-cyclohexane and 1.1 g of 4- (o-tolyl) -furazan-3-yl-carboxamide are added.

 

Claims (1)

PATENT CLAIM Process for the preparation of new Furazandertvaten of the general formula I, EMI2.1 in which Rt is hydrogen or a lower alkyl group and R2 is a lower alkyl group which is in the o or m position, characterized in that a compound of the general formula II, EMI2.2 in which R1 and R2 have the meaning given under formula I, according to Hoffmann, degrades to the amino compound of general formula I.