- Readily Reconfigurable Continuous-Stirred Tank Photochemical Reactor Platform
-
A new modular photochemical continuous stirred-tank reactor (CSTR) design is described, based upon the development of light-source units that can be fitted to the previously described fReactor CSTR platform. In addition to use in homogeneous photochemical reactions (e.g., photoredox-catalyzed hydroamination), these units are especially well suited to handling multiphasic mixtures, exemplified here in solid-liquid (Wohl-Ziegler bromination) and gas-liquid (photocatalytic oxidative decarboxylation) reactions. The use of slurries as input feeds allows for the intensification of photochemical brominations, while the modular nature of the system facilitates the simple integration of downstream reaction steps, exemplified here in a continuous synthesis of an intermediate for the antihypertensive drug valsartan.
- Blacker, A. John,Francis, Daniel,Kapur, Nikil,Marsden, Stephen P.
-
-
- PROCESS FOR THE PREPARATION OF VALSARTAN
-
The present invention relates to a process for the preparation of pure Valsartan (I) substantially free from impurities of formulae (Ia), (Ib), and (Ic), which comprises: (i) condensing 2-(4′-bromomethylphenyl)benzonitrile of formula (II) with L-valine methyl ester hydrochloride of formula (V) in the presence of a base in a solvent to produce N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester of formula (VI); (ii) treating the compound VI of step (i) with acid followed by treating with base to produce pure compound VI substantially free from dimeric impurity of formula (Via); (iii) reacting the pure compound of formula (VI) with n-valeryl chloride in the presence of a base to produce pure N-valeryl-N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester (VII) substantially free from alkene impurity of formula (Vila); (iv) reacting the compound of formula (VII) with trialkyltin chloride and a metal azide in a solvent at a reflux temperature to produce N-(1-oxopentyl)-N-[[2′-(2-tributyltinte-trazol-5-yl)-(1,1′-biphenyl)-4-yl]methyl]-(L)-valine methyl ester of formula (VHIb) free from thermal degradation impurity (Villa); (v) hydrolyzing the compound of formula (VHIb) in the presence of alkaline conditions to produce Valsartan (I).
- -
-
Paragraph 0053; 0054; 0055
(2013/06/26)
-
- Synthesis and biological evaluation of novel potent angiotensin II receptor antagonists with anti-hypertension effect
-
A series of novel angiotensin II type 1 receptor antagonists were prepared. Radioligand binding assay suggested that compounds 1b and 1c could be recognized by the AT1 receptor with an IC50 value of 1.6 ± 0.09 nM and 2.64 ± 0.7 nM, respectively. In vivo anti-hypertension experiments showed that compounds (1a, 1b, 1c, 1e) elicited a significant decrease in SBP and DBP of spontaneous hypertensive rats (SHRs). The antihypertensive effects maintained for 10 h, which indicated that these compounds had a favorable blood pressure-lowering effect. Acute toxicity testing suggested that the LD50 value of compound 1b was 2316.8 mg/kg which was lower than valsartan (LD50 = 307.50 mg/kg) but higher than losartan (LD50 = 2248 mg/kg). So they could be considered as novel anti-hypertension candidates and deserved for further investigation.
- Nie, Yong-Yan,Da, Ya-Jing,Zheng, Hao,Yang, Xiao-Xia,Jia, Lin,Wen, Cai-Hong,Liang, Li-Sha,Tian, Juan,Chen, Zhi-Long
-
p. 2747 - 2761
(2012/05/20)
-
- AN IMPROVED PROCESS FOR THE PREPARATION OF VALSARTAN
-
The present invention relates to a process for the preparation of pure Valsartan (I) substantially free from impurities of formulae (la), (lb), and (Ic), which comprises: (i) condensing 2-(4'-bromomethylphenyl)benzonitrile of formula (II) with L-valine methyl ester hydrochloride of formula (V) in the presence of a base in a solvent to produce N-[(2'-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester of formula (VI); (ii) treating the compound VI of step (i) with acid followed by treating with base to produce pure compound VI substantially free from dimeric impurity of formula (Via); (iii) reacting the pure compound of formula (VI) with n-valeryl chloride in the presence of a base to produce pure N-valeryl-N-[(2'-cyanobiphenyl-4-yl)methyl]- (L)-valine methyl ester (VII) substantially free from alkene impurity of formula (Vila); (iv) reacting the compound of formula (VII) with trialkyltin chloride and a metal azide in a solvent at a reflux temperature to produce N-(l-oxopentyl)-N-[[2'-(2- tributyltintetrazol-5-yl)-(l, l '-biphenyl)-4-yl]methyl]-(L)-valine methyl ester of formula (VHIb) free from thermal degradation impurity (Villa); (v) hydrolyzing the compound of formula (VHIb) in the presence of alkaline conditions to produce Valsartan (I).
- -
-
Page/Page column 14-15
(2012/01/14)
-
- AN IMPROVED PROCESS FOR THE PREPARATION OF VALSARTAN
-
The present invention relates to an improved process for the preparation of valsartan compound of formula-1 through novel intermediate compounds. It also relates to a novel process for the preparation of amorphous form of valsartan.
- -
-
Page/Page column 16
(2010/11/29)
-
- Synthesis of valsartan via decarboxylative biaryl coupling
-
(Chemical Equation Presented) An efficient synthesis of the angiotensin II inhibitor valsartan (Diovan) is presented. Two routes were evaluated, both making use of an advanced version of our decarboxylative coupling for the construction of the biaryl moiety. Thus, in the presence of a catalyst system consisting of copper(II) oxide, 1,10-phenanthroline, and palladium(II) bromide, 2-cyanocarboxylic acid was coupled with 1-bromo(4-dimethoxymethyl)benzene in 80% yield and with 4-bromotoluene in 71% yield. The valsartan synthesis using 1-bromo(4-dimethoxymethyl)benzene was completed in four steps overall with a total yield of 39%, via a novel route that presents substantial economical and ecological advantages over the literature process, as it is more concise and stoichiometric amounts of expensive organometallic reagents are avoided.
- Goossen, Lukas J.,Melzer, Bettina
-
p. 7473 - 7476
(2008/02/12)
-
- ACYL COMPOUNDS
-
Compounds of the formula STR1 in which R 1 is an aliphatic hydrocarbon radical which is unsubstituted or substituted by halogen or hydroxyl, or a cycloaliphatic or araliphatic hydrocarbon radical; X 1 is CO, SO 2, or--O--C(=O)--with the carbon atom of the carbonyl group being attached to the nitrogen atom shown in formula I; X 2 is a divalent aliphatic hydrocarbon radical which is unsubstituted or substituted by hydroxyl, carboxyl, amino, guanidino or a cycloaliphatic or aromatic radical, or is a divalent cycloaliphatic hydrocarbon radical, it being possible for a carbon atom of the aliphatic hydrocarbon radical to be additionally bridged by a divalent aliphatic hydrocarbon radical; R. sub.2 is carboxyl which, if desired, is esterified or amidated, substituted or unsubstituted amino, formyl which, if desired, is acetalized, 1H-tetrazol-5-yl, pyridyl, hydroxyl which, if desired, is etherified, S(O) m--R where m is 0, 1 or 2 and R is hydrogen or an aliphatic hydrocarbon radical, alkanoyl, unsubstituted or N-substituted sulfamoyl or PO n H 2 where n is 2 or 3; X 3 is a divalent aliphatic hydrocarbon; R 3 is carboxyl, 5-tetrazolyl, SO. sub.3 H, PO. sub.2 H 2, PO 3 H 2 or haloalkylsulfamoyl; and the rings A and B independently of one another are substituted or unsubstituted; in free form or in salt form, can be prepared in a manner known per se and can be used, for example, as medicament active ingredients.
- -
-
-