Application of alcohol to cis- and trans-2-alkoxymethylene-3-alkoxypropionitrile and 2-dialkoxymethyl-acrylonitrile, with acid or alkali as a catalyst, was found to effect facile addition of the alcohol to form the acetal-type compounds, 2-dialkoxymethyl-3-alkoxypropionitriles, evidenced by their elemental analytical values and infrared absorption spectra. In this reaction, some 2-dialkoxymethyl-acrylonitriles formed and transetherification of the starting 2-alkoxymethylene-3-alkoxypropionitriles and the formed 2-alkoxymethylene-3-alkoxypropionitriles was observed.
Die Oxazoliumsalze (I) reagieren mit den Acylphosphonaten (II) in Gegenwart von Triäthylamin bei -50 bis -60°C zu den Phosphorsäureestern (III), die mit stark alkalischen Ionenaustauschern oder wäßrigem Triäthylamin zu Oxazinonen (IV) und/oder Azetidinonen (V) weiterreagieren.
Following the discovery for a formation of 1-aryl-4-cyanopyrazole by the reaction of 2-(1-ethoxy-1-methoxymethyl)-3-ethoxypropionitrile (I) and arylhydrazine, the behavior of the nitrile group and the alkoxyl in 2-position in this condensation reaction was examined. The reaction of 2-(1-ethoxy-1-methoxymethyl) propionitrile (IV), 2-(1-ethoxy-1-methoxymethyl) propylamine (V), and 2-(1-ethoxy-1-methoxymethyl)-3-ethoxypropylamine (VI) with phenylhydrazine or p-nitrophenylhydrazine afforded 1-aryl-4-methyl-5-aminopyrazoles (XIII) and (VII) from (IV), 1-aryl-4-methylpyrazoles (XII and IX) from (VI), and (IX) from (V). The structure of these products was established from their infrared and ultraviolet spectra, and elementary analytical values. Deamination of (VII) by diazotization gives (IX), oxidation of (IX) with potassium permanganate gives 1-p-nitrophenyl-4-carboxypyrazole (X), nitration of (XII) gives (IX), and reduction of (IX) over palladium-carbon affords the amino compound (XI). These facts indicate the correctness of the structure of the reaction products (VII), (IX), (XII), and (XIII).Foregoing results indicate that the nitrile group in (IV) behaves in ordinary reaction type and the alkoxyl in (VI) does not take part directly in pyrazole condensation but acts toward aromatization. The compound (V) is somewhat less reactive than (VI) but both undergo cyclization to pyrazole compound accompanied by dehydrogenation. These facts are interesting in connection with results described in the preceding paper.
The new thiamine derivatives, O-substituted derivatives of thiamine propyl disulfide, disulfide derivatives of thiamine and 2-hydroxy-3-carbamoyloxypropyl, 2-ethoxycarbonylethyl, 2-ethoxycarbonyloxyethyl, and their O-substituted derivatives were prepared. Also, O-2-tetrahydropyranyl derivatives of S-alkoxycarbonyl thiamine and thiamine propyl disulfide were prepared, and their primary screening tests were made.
Reaction of 2-methyl-3-ethoxy-3-methoxypropionitrile (I), 2-methoxymethylenepropionitrile (II), or 2-ethoxymethylenepropionitrile (III) and methylhydrazine in ethanol containing conc. hydrochloric acid gives 5-amino-1, 4-dimethylpyrazole (V) and 3-amino-1, 4-dimethylpyrazole (VI) in approximately equal quantities. Further reaction of VI with I, II, or III gives 1, 3, 6-trimethylpyrazolo[1, 5-a]pyrimidin-7(1H)-one (VIII).Similarly, reaction with hydrazine hydrate gives 4-methyl-5-aminopyrazole (X) which is led to 3, 6-dimethyl-7-aminopyrazolo[1, 5-a]pyrimidine (XI). Hydrolysis of XI followed by methylation gives VIII. On the other hand, methylation of XI gives 3, 4, 6-trimethyl-7-imino-4, 7-dihydropyrazolo[1, 5-a]pyrimidine (XIII), whose hydrolysis affords the 7-one compound (XIV). Reaction of VIII with hydrazine hydrate results in its cleavage into 4-methyl-4-pyrazolin-3-one (IX) and 1, 4-dimethyl-3-aminopyrazole (VI), while XIV undergoes similar cleavage into IX and 4-methyl-5-methylaminopyrazole (XV). These reactions confirm the structure of these compounds. It should be noted that XI has a fairly strong antifebrile and analgesic activity.
Reaction of thiamine Na salt with COS gave the compound having 1, 2-dithiolane ring (IV). This compound was readily obtained from the reaction of thiamine anhydride (I) and H2S in DMF solution. Reaction of I with D2S gave deuterium incorporated derivatives and the mechanism for the formation of IV was suggested.
Abstract Die aus β‐Hydroxyäthylthiazolium‐Yliden und Isothiocyanaten hergestellten Cycloaddukte (I) liefern bei der Behandlung mit flüssigem Ammoniak unter Schwefelabspaltung die Iminoderivate (II).
