4727-29-1Relevant articles and documents
Kinetics and mechanism of the cleavage of phthalic anhydride in glacial acetic acid solvent containing aniline
Damit, Emmy Fadhiza,Ariffin, Azhar,Niyaz Khan
, p. 9303 - 9313 (2008)
(Chemical Equation Presented) Apparent second-order rate constants (k napp) for the nucleophilic reaction of aniline (Ani) with phthalic anhydride (PAn) vary from 6.30 to 7.56 M-1 s-1 with the increase of temperature from 30 to 50°C in pure glacial acetic acid (AcOH). However, the values of pseudo-first-order rate constants (k s) for the acetolysis of PAn in pure AcOH increase from 16.5 × 10-4 to 10.7 × 10-3 s-1 with the increase of temperature from 30 to 50°C. The values of knapp and ks vary from 5.84 to 7.56 M-1 s-1 and from 35.1 × 10-4 to 12.4 × 10-4 s-1, respectively, with the increase of CH3CN content from 1% to 80% v/v in mixed AcOH solvents at 35°C. The plot of ks versus CH 3CN content shows a minimum (with 104 ks = 4.40 s-1) at 50% v/v CH3CN. Similarly, the variations of knapp and ks with the increasing content of tetrahydrofuran (THF) in mixed AcOH solvent reveal respective a maximum (with knapp = 17.5-15.6 M-1 s-1) at 40-60% v/v THF and a minimum (with ks = ～ 0-1.2 ～ 10-4 s-1) at 60-70% v/v THF. The respective values of ΔH* and Δ S * are 15.3 ± 1.2 kcal mol-1 and -20.1 ± 3.8 cal K-1 mo-1 for ks and 1.1 ± 0.5 kcal mol-1 and -51.2 ± 1.7 cal K-1 mol-1 for knapp, while the values of kn (= k napp/fb with fb representing the fraction of free aniline base) are almost independent of temperature within the range 30-50°C. A spectrophotometric approach has been described to determine fb in AcOH as well as mixed AcOH-CH3CN and AcOH-THF solvents. Thus, the observed data, obtained under different reaction conditions, have been explained quantitatively. An optimum reaction condition, within the domain of present reaction conditions, has been suggested for the maximum yield of the desired product, N-phenylphthalamic acid.
Synthetic method of epinastine hydrochloride
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Paragraph 0031-0032, (2020/12/15)
The invention relates to a synthesis method of epinastine hydrochloride. The method comprises the following steps: reacting phthalic anhydride with aniline to obtain a compound 1, reacting the compound 1 with polyphosphoric acid under certain conditions to perform cyclization to obtain a compound 2, reducing carbonyl of the compound 2 under certain conditions to obtain a compound 3, and carrying out chlorination reaction on the compound 3 to obtain a compound 4, carrying out cyano substitution reaction on the compound 4 to obtain a compound 5, reducing the compound 5 by using a carbon-nitrogenunsaturated bond to obtain a compound 6, reacting the compound 6 with cyanogen bromide, and forming hydrochloride by using hydrochloric acid to obtain a compound 7; according to the method, the epinastine hydrochloride is prepared from bulk chemical products, is extremely low in price and mild in reaction condition, avoids the use of azide compounds, and the method is suitable for large-scale industrial production. The prepared epinastine hydrochloride is high in purity and low in cost, and has higher market competitiveness.
Synthetic method of plant growth regulator
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Paragraph 0052; 0053; 0055; 0060; 0091-0094, (2017/11/18)
The invention discloses a synthetic method of plant growth regulator, which includes steps of 1), mixing a compound shown in formula (I), a compound shown in formula (II) and first alkali catalyst; performing ammonolysis reaction to obtain a compound shown in formula (III); 2), mixing the compound shown in formula (III) and prepared in step 1) with water to obtain mixed solution; performing hydrolysis reaction and acidification to prepare a compound shown in (IV), namely, the plant growth regulator, wherein R1 and R2 are independently selected from hydrogen, alkyl group, alkyl, alkynyl or halogen atom; the synthetic method is simple in method, the reaction product is high in yield; the compound shown in formula (III) in the product has high content.
Water mediated, environmentally friendly, step-wise, tandem & one-pot syntheses of 2-(1H-benzo[d]imidazole-2-yl)-N-arylbenzamides
Reddy, Yervala Dathu,Ramana Reddy, Chittireddy Venkata,Dubey, Pramod Kumar
, p. 2974 - 2979 (2014/01/06)
Water mediated and environmentally friendly, step-wise, tandem & one-pot syntheses of 2-(1H-benzo[d]imidazole-2-yl)-N-arylbenzamide derivatives have been developed by simply combining phthalic anhydride, anilines and phenylenediammonium dihydrogenphosphate. This reaction has an easy workup, provides excellent yields, and uses water as the solvent which is considered to be relatively environmentally benign.
An expeditious synthesis of imides from phthalic, maleic and succinic anhydrides and chemoselective C=C reduction of maleic amide esters
Kumar, Padam Praveen,Reddy, Y. Dathu,Kumari, Y. Bharathi,Devi, B. Rama,Dubey
, p. 392 - 398 (2014/05/06)
Phthalic, maleic and succinic anhydrides have been reacted with aromatic amines to obtain the corresponding monoacid monoamides. The latter have been each transformed into the corresponding cyclic imide derivatives by treating with SOCl2. Alternatively, anhydrides have been reacted with methanolic KOH to obtain monomethyl ester derivatives which on reaction with aromatic amines in the presence of EDC. HCl and HOBt give cyclic imide derivatives. Reaction of monoacid monoamides independently, with SOCl 2 at 0-5°C give the monoamide monoester derivatives. Treatment of monoamide monoester of malic anhydride with NaBH4 leads to the unusual reduction of C=C grouping as well as the carbonyl group of the ester group to from monoamide monoalcohol of succinic anhydride. Preparation of monoamide monoalcohol of succinic anhydride can also be achieved by chemoselective reduction of monoamide monoester of malic anhydride with Mg turnings yielding monoamide monoester of succinic anhydride followed by reduction of the latter with NaBH4.
Aza-DielsAlder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome
Jha, Amitabh,Chou, Ting-Yi,ALJaroudi, Zainab,Ellis, Bobby D.,Cameron, T. Stanley
supporting information, p. 848 - 857 (2014/05/06)
The synthesis of 5-substituted 6,6a-dihydroisoindolo[2,1-a]quinolin-11(5H)- ones via [4 + 2] imino-DielsAlder cyclization from N-aryl-3- hydroxyisoindolinones and N-vinyl lactams under Lewis acid-catalysed anhydrous conditions is reported. Reactions of N-(2-substituted-aryl)-3- hydroxyisoindolinones with N-vinylpyrrolidone under identical conditions resulted in the formation of 2-(2-substitued-aryl)-3-(2-(2-oxopyrrolidin-1-yl) vinyl)isoindolin-1-one analogues indicating steric hinderance as the cause of deviation. The probable mechanism of the reaction based on the results from X-ray crystallography and molecular modelling is discussed.
A facile and green synthesis of N-substituted imides
Kumar, Padam Praveen,Rama Devi,Dubey
, p. 1166 - 1171 (2013/09/24)
Anhydrides 1, 6 and 10 have been reacted, independently, with aromatic primary amines 2 in solid phase by simple physical grinding of reactants with p-toluenesulphonicacid as a catalyst to yield corresponding open chain derivatives, monoacid monoamides3,7 and 11 respectively. The latter have each been transformed into the corresponding cyclic derivatives, i.e. imides 5, 9 and 13 respectively in solid phase by simple physical grinding of each with K 2CO3, alkylating agent and tetrabutylammoniumbromide as a catalyst with short reaction times. These cyclic imides can also be obtained by physical grinding of each of 3, 7 and 11 with dicyclohexylcarbodimide as a dehydrating agent in solid phase.
Synthesis and in vitro evaluation of N-substituted maleimide derivatives as selective monoglyceride lipase inhibitors
Matuszak, Nicolas,Muccioli, Giulio G.,Labar, Geoffray,Lambert, Didier M.
experimental part, p. 7410 - 7420 (2010/04/30)
The endocannabinoid 2-arachidonoylglycerol (2-AG) plays a major role in many physiological processes, and its action is quickly terminated via enzymatic hydrolysis catalyzed by monoglyceride lipase (MGL). Regulating its endogenous level could offer therapeutic opportunities; however, few selective MGL inhibitors have been described so far. Here, we describe the synthesis of N-substituted maleimides and their pharmacological evaluation on the recombinant human fatty acid amide hydrolase (FAAH) and on the purified human MGL. A few N-arylmaleimides were previously described (Saario, S. M.; Salo, O. M.; Nevalainen, T.; Poso, A.; Laitinen, J. T.; Jarvinen, T.; Niemi, R. Characterization of the Sulfhydryl-Sensitive Site in the Enzyme Responsible for Hydrolysis of 2-Arachidonoylglycerol in Rat Cerebellar Membranes. Chem. Biol. 2005, 12, 649-656) as MGL inhibitors, and along these lines, we present a new set of maleimide derivatives that showed low micromolar IC50 and high selectivity toward MGL vs FAAH. Then, structure-activity relationships have been investigated and, for instance, 1-biphenyl-4-ylmethylmaleimide inhibits MGL with an IC50 value of 790 nM. Furthermore, rapid dilution experiments reveal that these compounds act as irreversible inhibitors. In conclusion, N-substituted maleimides constitute a promising class of potent and selective MGL inhibitors.
Chemoselective acylation of amines in aqueous media
Naik, Sarala,Bhattacharjya, Gitalee,Talukdar, Bandana,Patel, Bhisma K.
, p. 1254 - 1260 (2007/10/03)
Amines are efficiently acylated by both cyclic and acyclic anhydrides by dissolving them in an aqueous medium with the help of a surfactant, sodium dodecyl sulfate (SDS). Cyclic and acyclic anhydrides react with equal ease with an amine, and amines with various stereo-electronic factors react at the same rates with an anhydride. Chemoselective acylation of amines in the presence of phenols and thiols and of thiols in the presence of phenols has been achieved. No acidic or basic reagents are used during the reaction. No Chromatographic separation is required for isolation of the acylated products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by-products make the present method a green chemical process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
