Formation of Nitrosopyrazolidones and Pyrazolones from the Hydrazides of Unsaturated Acids was written by Muckermann, Ernst. And the article was included in Berichte der Deutschen Chemischen Gesellschaft in 1910.Recommanded Product: 51395-52-9 This article mentions the following:
Cinnamic hydrazide, PhCH : CHCONHNH2, prepared from ethyl cinnamate and hydrazine hydrate, crystallizes in bundles of colorless, slender, interlaced needles, m. 101°. It has been described previously as an oil. Yield, 52.1-4.3%. Hydrochloride, from absolute alc. HCl; crystalline, becomes yellow about 190°, m. and evolves gas 201°. Yield, 89.7-93.8%. Benzal derivative, light yellow flocks, softens about 170°, m. 180°. Yield, about 112% of the hydrazide. I-Nitroso-5-phenyl-3-pyrazolidone, formula (I) below, is prepared from cinnamic hydrazide, HCl and NaNO2; slender, colorless needles, becomes yellow about 115°, m. and decomposes 127-8°. It burns with a smoky flame, is soluble in dilute aqueous NaOH and exhibits Liebermann’s reaction. Yield, 86-90% of the hydrazide hydrochloride. When treated with glacial AcOH and Br it gives 3-phenyl-4,4-dibromo-5-pyrazolone (II); m. 198° not 189°. Boiling, concentrate HCl hydrolyzes (I) to cinnamic acid, but dilute H2SO4 (d. 1.06), under similar conditions, converts it into 4-isonitroso-3-phenylpyrazolone (III), gas being evolved during the earlier stages of the reaction. Crotonic hydrazide could only be obtained as an oil which was not pure. It is somewhat unstable. Hydrochloride, MeCH:CHCONHNH2.HCl, slender, colorless, rather unstable needles, m. and evolves gas 173°. Yield, 87.9%. Benzal derivative, light yellow and insoluble, m. 72°. Yield, 60% of the hydrazide. 1-Nitroso-5-methyl-3-pyrazolidone is prepared in a similar manner to the Ph derivative (1); colorless, lustrous plates, m. and evolves gas 131°. It is soluble in aqueous NaOH or NH3, gives a cherry-red color with FeCl3 and exhibits Liebermann’s reaction. Yield, 60-76% of the hydrazide hydrochloride. Glacial AcOH and Br, at 0°, convert it into 3-methyl-4-bromo-5-pyrazolone (IV), which was prepared for comparison from 3-methylpyrazolone; colorless, thick, hexagonal plates, m. 182°. Yield about 100% of the nitroso compound. Under similar conditions, at the ordinary temperature, the nitroso compound gives 3-methyl-4,4-dibromo-5-pyrazolone. In the experiment, the researchers used many compounds, for example, 4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9Recommanded Product: 51395-52-9).
4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9) belongs to pyrazole derivatives. As is the case with imidazoles, the pyrazole ring offers many opportunities to create new multiring systems that incorporate this heterocycle. The pyrazole ring is resistant to oxidation and reduction but the groups, such as alkyl and formyl attached to the ring, are oxidized to respective acids. Only electrolytic oxidation, ozonolysis, and a strong base cause ring opening.Recommanded Product: 51395-52-9
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics