76457-44-8Relevant academic research and scientific papers
Reactions of p-Coumaric acid with nitrite: Product isolation and mechanism studies
Torres y Torres, Janelle L.,Rosazza, John P. N.
, p. 1486 - 1492 (2007/10/03)
p-Coumaric acid (1) is an abundant plant phenolic acid, a dietary chemoprotectant, and an antioxidant. The chemoprotective properties of I were demonstrated in vitro by its reaction with NaNO2 in H2O over a range of pH values. The reaction pathway of I with nitrite is dependent on pH. 4-Hydroxybenzaldehyde (3, 16%), 1′,4-dihydroxybenzeneacetaldehyde oxime (5, 59%), and 4-hydroxy-1′-oxo-benzeneacetaldehyde aldoxime (7, 26%) and 7-hydroxy-1,2(4H)-benzoxazin-4-one (11, 6%) were each formed at pH 2, whereas 4-(2-oxido-1,2,5-oxadiazol-3-yl)phenol (13) was formed at pH 3 (6%) and pH 7 and 10 (both 1%). Products were isolated and characterized by NMR and MS spectral analyses. Formation of benzoxazinone (11) requires the 4-phenolic functional group and the conjugated propenoic acid side chain of p-coumaric acid. The mechanism for nitrosation at pH 2 was examined by reacting I in H218O/NaNO2.
Process for preparing substituted and unsubstituted arylalkylamines
-
, (2008/06/13)
An arylisonitrosoalkanone is hydrogenated in the presence of a noble metal catalyst and a weak carboxylic acid to form an arylalkanolamine which is then hydrogenated in the presence of a strong mineral acid and the transition metal catalyst to form an arylalkylamine. When the arylisonitrosoalkanone is an isonitrosoacetophenone, the isonitrosoacetophenone is prepared by one of two methods. In the first method, a substituted or an unsubstituted isonitrosoacetophenone is prepared from a corresponding substituted or unsubstituted acetophenone by oxidizing the acetophenone to form a substituted or an unsubstituted phenylglyoxalacetal in a reactor, hydrolyzing the phenylglyoxal acetal in the same reactor to form a corresponding substituted or unsubstituted phenylglyoxal, and condensing the phenylglyoxal with hydroxylamine or a salt thereof in the same reactor to form the substituted or unsubstituted isonitrosoacetophenone. Alternatively, the substituted or unsubstituted isonitrosoacetophenone is prepared from the corresponding substituted or unsubstituted acetophenone by reacting the substituted or unsubstituted acetophenone in water with a source of a nitrosonium ion in the presence of a strong acid to form a corresponding substituted or unsubstituted phenylglyoxal, and condensing the phenylglyoxal with hydroxylamine or a salt thereof to form the substituted or unsubstituted isonitrosoacetophenone. In either method, any strong acid that might be present in the reaction mass following the condensation to the isonitrosoacetophenone shall be removed therefrom prior to initiating the hydrogenation of the isonitrosoacetophenone to the arylalkanolamine.
Process for the preparation of arylalkylamines and substituted arylalkylamines
-
, (2008/06/13)
Arylalkylamines (as the hydrochloride salt), e.g. tyramine hydrochloride, are prepared by hydrogenating substituted or unsubstituted aryl-α-oximinoalkyl ketones, e.g. p-hydroxyisonitroacetophenone, in either in an aqueous reaction medium comprising hydrochloric acid, essentially without the presence of a lower alkyl alcohol in said reaction medium, or in an aqueous reaction medium comprising water, hydrochloric acid, and a lower alkyl alcohol, wherein the alcohol comprises less than about 90% by volume of the reaction medium. A substituent on the aryl portion of the aryl-α-oximinoalkyl ketone must be on a position which activates the aromatic ring.
Structure Determinations of Oxadiazole Ring Systems
Pluecken, Udo,Winter, Werner,Meier, Herbert
, p. 1557 - 1572 (2007/10/02)
The compounds 10 - 15 generated in the reaction of p-hydroxyphenylcinnamic acid 7 with HNO2, were isolated and spectroscopically characterized. 10 is supposed in the literature to be a 1,2,3-oxadiazole 3-oxide 5; it actually has the constitution of a furoxan, and crystallizes in the space group P21/c = 2 ? (I)>.The compound with one oxygen less is the corresponding furazan 11.Alkaline degradation of the main products 10 and 12 leads to 13 and 25 - 27 and to 28, respectively.
Process for the preparation of 1-(m- and p-hydroxyphenyl)-2-aminoethanol
-
, (2008/06/13)
The present invention relates to a process for the preparation of 1-(m- and p- hydroxyphenyl)-2-aminoethanol which consists of converting an m- or p- hydroxyacetophenone to an isonitrosoketone followed by hydrogenation of the isonitrosoketone. These compounds are sympathomimetics which produce vasoconstricting and cardiotonic effects.
