DE206453C - - Google Patents

Description

S-

.C

PATENT LETTERING

- JVr 206453 CLASS 12 / Λ GROUP

Patented in the German Empire on July 26, 1907.

According to the investigations by W. Traube (Reports 33 [1900], pp. 1371, 3035 and Annalen 331 [1904], pp. 64, 73 and 81) the isonitroso compounds of iminopyrimidines produced by the 4-iminopyrimidines treated with nitrous acid. ~

It has now been found that isonitroso compounds the general formula:

N (R) -CO

X: C

C-.NOH

■ N (R) -CvNH

. [X means for example: O, NH, S, CN-N;

R: hydrogen, alkyl or aryl)
can be obtained directly by isonitrosocyanoacetates, which can be obtained by the action of nitrous acid on cyanoacetates (Ann: de chim. et de phys. ¹ 7th scr. Vol. ι [1894], p. 507) with urea or its Derivatives such as thiourea, guanidine, dicyandiamide, guanylurea, biuret, AUophanic acid ester or the substitution products of these 'bodies are condensed with the help of alkaline agents. The bodies serve as the starting material for the preparation of derivatives of purine.

The formation of a six-membered ring did not occur in the present process to be foreseen with certainty, since by no means all derivatives of the malonic ester like this itself react with urea to form six-membered rings. So it is z. B. not possible from urea and mesoxalic acid estef Aloxan can be obtained with the aid of sodium ethylate. Urea reacts with mesoxalic acid rather with the formation of allantoin, i.e. a five-membered ring (see Richter chemistry der Carbonverbindungen, 10th edition, 1st volume [1903], p. 587).

It is more precisely known that urea and also guanidine have ketone and aldehyde acids also act to form five-membered rings. So you get z. B. Iminoallantoin from glyoxylic acid and guanidine and from pyruvic acid and urea pyruvil, which is also a five-membered Ring contains (see Richter op. Cit. P. 597).

Nevertheless it was known (Ann. De chim. Et de phys. 7. scr. Vol. 1 [1894], pp. 520/521 and Annalen 209 [1881], p. 214) that the isonitroso group in isonitrosocyanoacetate and isonitrosomalone ester is resistant to alkali and alkali alcoholates, it was therefore not to foresee that the technically valuable 4 - imino - 5 - isonitrosopyrimidine derivatives at all and these bodies would form smoothly and with good yields.

Example i.

46 parts of sodium are dissolved in 700 parts of absolute alcohol and 60 parts Urea and 142 parts of isonitrosocyanoacetate offset. The mixture is then heated on the water bath for 2 hours and the alcohol is distilled off. The residue is then dissolved in water and after Acidification. the excreted 2x6-dioxy-4-imino-5-isonitrosopyrimidine from the solution (see Ber. 33 [igoo], p. 1382) nitrided and dried.

Claims (1)

Example 2. 138 parts of alcohol-free sodium ethylate are mixed with 142 parts of isonitrosocyanoacetate and 88 parts of dimethylurea suspended in 1000 parts of dry benzene and , the suspension thus obtained is heated on the water bath for 4 hours. From the filtered The sodium salt becomes the ι · 3 - dimethyl - 2 · 6- dioxy ^ -imino-S-isonitroso- ■ pyrimidin (Ber. 33 [1900], pp. 3052/3053) obtained. Instead of sodium ethylate, finely divided sodium can also be used with equal success State to be applied. The dimethyl urea can also be replaced by other alkyl or aryl derivatives of urea, thiourea or guanidine or their derivatives be replaced. Example 3. 78 parts of potassium are in 1000 parts of methyl alcohol dissolved and this solution after the addition of 142 parts of isonitrosocyanoacetic acid S5 ethyl ester and 88 parts of dicyandiamide for 3 hours heated on the water bath. The precipitated potassium salt is filtered off and the 2-cyanimino-4-imino-5-isonitroso-6-oxypiri- ■ separated by acidification. Instead of dicyandiamide, guanylurea can also be used will. The new nitroso compound forms thin red needles which 'in water, Alcohol, ether, benzene are insoluble. With alkalis it gives poorly soluble in water, red colored salts. Example 4. 59 parts of guanidine and 142 parts of ethyl isonitrosocyanoacetate are dissolved in 500 parts of alcohol and this solution after addition heated by 80 parts of finely ground sodium amide * for 4 hours on the water bath. That The sodium salt formed is filtered off and the 2x4-diimino-6-oxy-5-isonitrosopyrimidine is obtained from it by acidification (Ber. 33 [1900], p. 1376) deposited. Instead of the sodium amide, other alkaline condensing agents such as Disodium cyanamide, can be used. The guanidine can of course also through its Alkyl or aryl substitution products are replaced. Example 5. 116 parts are added to a solution of 46 parts of sodium in 750 parts of absolute alcohol Acetylmethylurea and 142 parts of isonitrosocyanoacetyl ethyl ester. The mixture is then heated for 3 hours on the water bath The sodium salt formed is filtered off and the free 3 - methyl - 2 · 6 - dioxy - 4 - imino - 5 - isonitrosopyrimidine is obtained therefrom (Ber. 33 [1900], p. 3040) by; Acidification deposited. The acetylmethylurea can by an-. other acyl derivatives, such as. B. allophanoic acid esters, Biuret, guanylurea. Other esters of isonitrosocyanoacetic acid have a similar effect. Ρλτενϊ claim; Process for the preparation of 4-imino- ■■ ' '5-isonitrosopyrimidine derivatives, consisting in that one'urea, whose waste. Comes ocler substitution products of this body in the presence of alkaline Condensing agents on isonitrosocyanate vinegar ester to act. otoniicKT m drr