151870-45-0

Upstream product

• 53012-96-7 4-(4-chlorophenyl)-3-methyl-4-oxobutyronitrile 
• 52240-25-2 4-(4-chlorophenyl)-3-methyl-4-oxobutanoic acid 
• 104-88-1 4-chlorobenzaldehyde 
• 85633-96-1 3-methyl-4-oxo-4-(3'-nitro-4'-chloro-phenyl)-butyric acid 

Downstream Products

• 124939-14-6 6-[4-(2-tert.-butoxycarbonylamino)ethylamino-3-nitro-phenyl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone 
• 124939-49-7 6-[4-(4-phthalimidomethyl-piperidin-1-yl)-3-nitro-phenyl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone 
• 124939-15-7 6-[4-(3-tert.-butoxycarbonylamino)propylamino-3-nitro-phenyl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone 
• 124939-05-5 6-[3-nitro-4-(1-piperazinyl)-phenyl]-4,5-dihydro-5-methyl-3(2H)-pyridazinone 
• 85634-04-4 5-methyl-6-(1'-benzyl-benzotriazol-5'-yl)-4,5-dihydro-3(2H)-pyridazinone 
• 85634-12-4 5-methyl-6-(3'-amino-4'-isopropylamino-phenyl)-4,5-dihydro-3(2H)-pyridazinone 
• 85634-10-2 5-methyl-6-(3'-amino-4'ethylamino-phenyl)-4,5-dihydro-3(2H)-pyridazinone 

Relevant academic research and scientific papers

Synthesis of novel Pyridazinonylbenzotriazoles

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

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

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

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

Pyridazinone derivatives

A pyridizinone derivative of the formula I STR1 wherein R is F, Cl, Br, I or R1 R2 N, R1 and R2 are each H, C1-4 -alkyl or benzyl, R3, R4 and R5 are each H or C1-4 -alkyl and wherein it is only possible for R to be benzylamino, R3 to be CH3 and R4 to H at the same time if R5 is alkyl, and salts thereof display positive inotropic properties and vasodilative properties and can be used, in particular, as intermediate products in the production of other pharmaceutical agents.