52240-25-2Relevant academic research and scientific papers
Bio-based crotonic acid from polyhydroxybutyrate: synthesis and photocatalyzed hydroacylation
Fagnoni, Maurizio,Galletti, Paola,Jorea, Alexandra,Parodi, Adriano,Ravelli, Davide,Samorì, Chiara,Torri, Cristian
supporting information, p. 3420 - 3427 (2021/05/21)
A novel thermolytic distillation process was developed to depolymerize polyhydroxybutyrate (PHB) for the selective production of crotonic acid. The conditions adopted (170 °C, 150 mbar) were applied to pure PHB and PHB-enriched bacteria containing 60 and 30% of PHB, giving a recovery of crotonic acid of 92, 78 and 58%, respectively. The high efficiency of the developed process poses the basis for a drop-in production of bio-based crotonic acid, whose versatility as a platform chemical has been investigated through a photochemical approach. The photocatalytic addition (promoted by tetrabutylammonium decatungstate - TBADT) of aliphatic and aromatic aldehydes to crotonic acid took place under solar-simulated light irradiation. TBADT triggered thein situformation of valuable acyl radicals from the corresponding aldehydes, thus inducing the desired hydroacylationviaradical conjugate addition. Notably, the functionalization took place in a satisfactory yield quite independently of the adopted sample of crotonic acid (whether commercial or bio-based).
Synthesis of novel pyridazinonylbenzotriazoles
Reddy, S. Shashidhar,Vineel, B. George,Venkataiah,Naidu,Dubey
, p. 3633 - 3638 (2015/12/24)
4-Chlorobenzaldehyde (1) was reacted with crotononitrile (2) in the presence of sodium cyanide yielding 4-(4-chlorophenyl)-3-methyl- 4-oxobutyronitrile (3) which on refluxing with concentrated HCl gave 4-(4-chlorophenyl)-3-methyl-4-oxobutyric acid (4). The latter, on treatment with fuming nitric acid, yielded 4-(4-chloro-3-nitrophenyl)-3-methyl-4-oxobutyric acid (5), which on treatment with hydrazine hydrate gave 6-(4-chloro-3-nitrophenyl)-5-methyl-4,5-dihydro-2H-pyridazine-3-one (6). Azidation and reduction of 6 with sodium azide gave the amino derivative 7 which on reductive alkylation gave 10(a-i) followed by reduction with commercially available sodium hydrogen sulphide solution gave the substituted diamine derivative 11(a-i). The compound 7 directly undergoes reduction with sodium hydrogen sulphide yielding (8). Finally, 8 and 11(a-i) was converted into the target compounds by diazotized-cyclization with sodium nitrite giving pyridazinonylbenzotriazoles 9 and 12(a-i).
Synthesis of novel Pyridazinonylbenzotriazoles
Shashidhar Reddy,George Vineel,Venkataiah,Naidu,Dubey
, p. 3633 - 3638 (2015/12/30)
4-Chlorobenzaldehyde (1) was reacted with crotononitrile (2) in the presence of sodium cyanide yielding 4-(4-chlorophenyl)-3-methyl-4-oxobutyronitrile (3) which on refluxing with concentrated HCl gave 4-(4-chlorophenyl)-3-methyl-4-oxobutyric acid (4). The latter, on treatment with fuming nitric acid, yielded 4-(4-chloro-3-nitrophenyl)-3-methyl-4-oxobutyric acid (5), which on treatment with hydrazine hydrate gave 6-(4-chloro-3-nitrophenyl)-5-methyl-4,5-dihydro-2H-pyridazine-3-one (6). Azidation and reduction of 6 with sodium azide gave the amino derivative 7 which on reductive alkylation gave 10(a-i) followed by reduction with commercially available sodium hydrogen sulphide solution gave the substituted diamine derivative 11(a-i). The compound 7 directly undergoes reduction with sodium hydrogen sulphide yielding (8). Finally, 8 and 11(a-i) was converted into the target compounds by diazotized-cyclization with sodium nitrite giving pyridazinonylbenzotriazoles 9 and 12(a-i).
CRYSTALLINE PIMOBENDAN, PROCESS FOR THE PREPARATION THEREOF, PHARMACEUTICAL COMPOSITION AND USE
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, (2011/07/06)
The invention relates to a pharmaceutical composition containing pimobendan as an active ingredient. The invention also relates to a crystalline form of pimobendan, as well as to a combination of said crystalline form with at least one other therapeutically active ingredient. Moreover, the invention relates to uses of said crystalline form, as well as to a pharmaceutical composition containing it. Finally, the invention relates to a process for preparing a crystalline form of pimobendan.
Synthesis and biological activities of meribendan and related heterocyclic benzimidazolo-pyridazinones
Jonas, R,Klockow, M,Lues, I,Pruecher, H,Schliep, H J,Wurziger, H
, p. 129 - 140 (2007/10/02)
The synthesis of a new heterocyclic benzimidazolo-pyridazinones is described.The new compounds were evaluated as inotropic agents with 'calcium-sensitizing' effects. 5-Methyl-6--2,3,4,5-tetrahydro-pyridazin-3-one hydrochloride (meribendan) turned out to be the most interesting compound and was chosen for development as a positive inotrope. benzimidazole / calcium sensivity / cardiotonics / inotropes / phosphodiesterase / papillary muscle / pyridazinone
