DEC0010471MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: December 23, 1954. Advertised on May 3, 1956

GERMAN PATENT OFFICE

PA TENTAN REGISTRATION UNG

CLASS 12p GROUP 10 C 10471 IVb / 12 ρ

Dr. Wilhelm Kunze, Frankfurt / M.-Fechenheim

has been named as the inventor

Cassella Farbwerke Mainkur Aktiengesellschaft, Frankfurt / M.-Fechenheim

Process for the preparation of 1,4-dihydrazino-o-diazines

The i, 4-Dihydrazino-o-diazines have because of Their antihypertensive effects have high pharmaceutical value and can therefore be used as remedies or can be used as intermediate products in the manufacture of medicinal products.

It has been found that when exposed to at least 3 mol of hydrazine to ι mol 3-Amino-isoindolenines or their aza compounds which are in ι, ι-position two with alkyl or ίο aralkyl radicals contain etherified mercapto groups, at elevated temperature with elimination of ammonia and mercaptan in good yield the corresponding i, 4-dihydrazino-o-diazines are obtained. . ■

The reaction proceeds according to the following scheme: 15

NH-NH ₂

N
3

NH-NH ₂

ο MR MTJ

_Μ 3 PItI ₂ ^1Ν . · "· 2

NH

where R is a radical from the benzene or pyridine series and R _{1 is} alkyl or aralkyl radicals.

60'9 508/396

C 10471 IVb / 12p

The dialkyl mercapto-amino-isoindolenines used as starting materials can according to British Patent 711,433 in good yield from the corresponding aromatic or

.5 heterocyclic o-dinitriles are obtained.

The splitting off of the mercaptans begins at 60 °; the reaction products separate further heating to 80 ° crystalline.

It was surprising that the isoindolenines of the structure indicated, which easily convert into macrocyclic compounds of the phthalocyanine type, react with hydrazine to form an o-diazine ring, especially since the action of diamines, e.g. B. 2, 6-diaminopyridine in Isoindolenine by J. Chew. Soc. 1952, 5008, leads to macrocyclic compounds.

Compared to the method of the patent 845 200, in which 1, 4-Dihydrazinophthalazin from Phthalic acid dinitrile is obtained with about 58% yield, brings the application of the present Process an improvement in the yield, since the final stage proceeds with 85- to'o.o% yield, so that this, based on phthalic acid dinitrile, is 75%. This improvement is at Use of less accessible dinitriles of particular value.

Example i

25.2 parts 1, i-di- (äthylmerkapto) -3-amino-isoindolenine be entered at 20 ⁰ in a mixture of 60 parts of dioxane, 40 parts of hydrazine hydrate (8o ° / oig) and 4 parts of glacial acetic acid with stirring. The batch is stirred for 1 hour at 60 ° and 3 hours at 80 to 85 °, wherein: the ethylmercaptan split off with the ammonia can be obtained by condensation. At about 75 to 80 ° the crystalline separation of the reaction product begins. After cooling, it is filtered off with suction, washed with dioxane and water and recrystallized from water. 16.5 parts of i, 4-dihydrazinophthalazine are obtained in this way, which corresponds to a yield of 87.5%. The compound has the properties given in patent 845,200.

Example 2

10 parts of 1, i-di- (ethylmercapto) -3-amino-5-azaisoindolenine are introduced into a mixture of 30 parts of dioxane and 30 parts of hydrazine hydrate (80%) and 3 parts of acetic acid and stirred for 1 hour - <50 ° - and heated ^{to 85 0 for 3 hours.} At about 8d °, the crystallization of the reaction product begins ^; which is filtered off with suction after cooling and washed with dioxane and cold water. This gives 7.5 parts of the dried nitrogen atmosphere in the reaction product, mp 198 ⁰ (dec.), Which is deposited from the concentrated solution of the hydrochloride with Glauber's salt as the sulfate. 8.9 parts = 83% of the theory of the sulfate (melting point 203 ° decomp.) Of 1,4-dihydrazino-6-azaphthalazine, which is identical to the product obtained according to Patent 932,128, Example 2, are obtained.

Example 3

35 parts of 1, i-di- (benzylmerkapto -) - 3-amino-isoindolenine are heated in a mixture of 70 parts of dioxane and 70 parts of 8o ° / pc alcohol hydrazine hydrate and 8 parts of acetic acid for about 3 hours with stirring to 90 ^0th After cooling, the precipitated crystallized reaction product is filtered off with suction. 14.0 parts of 1,4-dihydrazinophthalazine = 79.5% of theory are obtained.

Claims (1)

PATENT CLAIM: Process for the preparation of 1, 4-dihydrazino-o-diazines, characterized in that 3-amino-isoindolenines or their aza compounds, the mercapto groups etherified with alkyl or aralkyl radicals in the 1, 1-position contain, the general formula, where R is a radical from the benzene or pyridine series and R _{1 is} alkyl or aralkyl radicals, is reacted with at least 3 mol of hydrazine at an elevated temperature. ® 609 508/396 4.56