21881-78-7Relevant articles and documents
Preparation method of nimodipine impurity
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Paragraph 0056; 0057; 0058; 0059; 0060, (2017/08/02)
The invention provides a preparation method of a nimodipine impurity. The method comprises the following steps: by using hydrogen chloride as a catalyst, mixing nimodipine and isopropanol, and heating to react to obtain the nimodipine impurity B. Compared with the prior art, the method is implemented by carrying out ester exchange reaction on the raw material nimodipine in the isopropanol solvent under the acid catalysis action of the hydrogen chloride; and thus, the method has the advantages of short technique and higher yield, and is simple to operate.
1-Methylimidazolium trifluoroacetate [Hmim]Tfa: Mild and efficient Bronsted acidic ionic liquid for Hantzsch reaction under microwave irradiation
Avalani, Jemin R.,Patel, Devji S.,Raval, Dipak K.
, p. 1091 - 1096 (2013/03/13)
One pot synthesis of 1,4-dihydropyridine derivatives was achieved via condensation of various β-ketoesters with aromatic/aliphatic aldehydes and ammonium acetate. The reaction was catalysed by a stable and reusable Bronsted acidic ionic liquid (IL), 1-methyl-imidazolium trifluoroacetate ([Hmim]Tfa), under microwave (MW) irradiation. The synergistic combination ofMWwith IL can potentially go a long way tomeet the increasing demand for chemical processes. This homogeneous catalytic procedure is simple and efficient. The catalyst can be reused at least four times with almost complete retention in its activity. Indian Academy of Sciences.
Synthesis and comparative pharmacological studies of 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylates with non-identical ester functions
Meyer,Bossert,Wehinger,Stoepel,Vater
, p. 407 - 409 (2007/10/02)
Michael-addition of 3-aminocrotonic acid ester 7 to aralkylidene acetoacetic acid esters 6 is followed by ring closure to give novel 4-aryl-1,4-dihydro-2,6-dimethyl-pyridine-3,5-dicarboxylates 8 with non-identical ester functions. In the series of 3-nitrophenyl derivatives (8, Ar=3-nitrophenyl) the pharmacological activities (coronary vasodilation, anti-hypertensive activity) of the asymmetrically substituted derivatives are shown to be superior to those of the corresponding symmetrically substituted derivatives in many cases. One representative of this class 3-ethyl-5-methyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedica rboxylate (nitrendipine, Bay e 5009, No. 3) was selected for further development as an antihypertensive drug.