cas 5744-40-1, Ethyl 1,3-dimethylpyrazole-5-carboxylate

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1-methyl-3-((methylamino)methyl)-1H-pyrazole-5-nitrile synthesis method
The invention belongs to the technical field of medicine and relates to a 1-methyl-3-((methylamino)methyl)-1H-pyrazole-5-nitrile synthesis method. Diethyl oxalate and acetone are easily acquirable andused as starting materials to obtain 1-methyl-3-((methylamino)methyl)-1H-pyrazole-5-nitrile through 7-step reaction including condensation, cyclization, methylation, amidation, oxidation, brominationand amination. By adoption of the method, preparation of 1-methyl-3-((methylamino)methyl)-1H-pyrazole-5-nitrile which is a key intermediate of antitumor drug lorlatinib (PF-06463922) is realized, thetotal yield reaches 5.7% or above, and simplicity in operation, convenience in aftertreatment, short time consumption and low cost are realized while industrialization can be realized beneficially. The intermediate and 5-fluoro-3-methyl isobenzofuran-1(3H)-ketone are subjected to reaction steps including ammonolysis, substitution, coupling, chiral resolution and the like to finally synthesize lorlatinib, and a novel method is provided for synthesis of the antitumor drug lorlatinib.
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(2019/01/14)

New pyrazolium-carboxylates as structural analogues of the pseudo-cross-conjugated betainic alkaloid nigellicine
Pyrazolium-3-carboxylates were examined as relatives of the betainic alkaloid Nigellicine and as new examples of the sparsely populated class 16 of heterocyclic pseudo-cross-conjugated mesomeric betaines (PCCMB). The title compounds were prepared in a 4-step procedure starting from β-diketo compounds 8 which were cyclized with substituted hydrazines. The resulting isomeric pyrazole esters 9 and 10 were separated and subsequently quaternized with dimethyl sulfate in the presence of nitrobenzene to pyrazolium esters 11 and 12. Saponification was best accomplished in diluted sulfuric acid, which resulted in the formation of the pseudo-cross-conjugated mesomeric betaines 13 and 14 in one step. Protonation to the corresponding carboxylic acids required the treatment of the betaines with tetrafluoroboric acid in dichloromethane. The effect of negative solvatochromism proves the charge separation in the ground state of the molecules. X-ray crystallographic analyses, semiempirical calculations, and ESI mass spectrometric measurements were performed to gain knowledge about the phenomenon of pseudo-cross-conjugation.
Schmidt, Andreas,Habeck, Tobias,Kindermann, Markus Karl,Nieger, Martin
p. 5977 - 5982
(2007/10/03)

Haloacetylated enol ethers. 11 [16]. Synthesis of 1-methyl- and 1- phenyl pyrazole-3(5)-ethyl esters. A one-pot procedure
A one-pot synthesis of 1-methyl- and 1-phenylpyrazole-3(5)-ethyl esters 2,3a-e by the cyclocondensation of β-alkoxyvinyl trichloromethyl ketones 1a- e with methyl and phenyl hydrazine hydrochloride under mild conditions, is reported. A study using compounds la-e with different substituents proved that these are versatile building blocks for the synthesis of pyrazole derivatives, having a 3(5)-ethoxycarbonyl substituent in good yields (60- 89%). The hydrazine and β-alkoxyvinyl trichloromethyl ketone substituent effects on the reaction regiochemistry on the formation of the 1,3- and 1,5- isomer were observed.
Martins, Marcos A. P.,Freitag, Rogerio A.,Da Rosa, Adriano,Flores, Alex F. C.,Zanatta, Nilo,Bonacorso, Helio G.
p. 217 - 220
(2007/10/03)

Systemic fungicides. The synthesis of certain pyrazole analogues of carboxin
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Huppatz
p. 135 - 147
(2007/10/02)

Compounds and compositions
Fungicidal compositions comprising as an active ingredient a compound of the general formula I STR1 wherein either R1 or R2 is the group STR2 in which X is an oxygen atom or a sulphur atom and R5 is straight chain alkyl group of 1 to 8 carbon atoms, branched chain alkyl group of 1 to 8 carbon atoms, cyclic alkyl group of 3 to 8 carbon atoms, alkenyl group, alkynyl group, hydroxyalkyl group phenyl group or a mono-, di- or tri- substituted phenyl group with substituents, which may be the same or different, chosen from the group consisting hydrogen alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxy, phenyl, halogen, trifluoromethyl, thiocyanate, nitro, cyano, amino, carboxy, alkoxycarbonyl, carbamoyl, N-alkylcarbamoyl and N,N-dialkylcarbamoyl; when R1 is the group STR3 then R3 is hydrogen, alkyl, alkenyl alkynyl, hydroxyalkyl, phenyl, CH2 CF3 or the group --CH2 COOR6 wherein R6 is alkyl, phenyl or substituted phenyl, and R2 and R4, which may be the same or different, are hydrogen, alkyl, alkenyl, alkynyl, hydroxalkyl, alkoxy, phenyl, halogen, trifluoromethyl, thiocyanate, nitro, cyano, amino, carboxy, alkoxycarbonyl, carbamoyl, N,alkylcarbamoyl, N,N-dialkylcarbamoyl, hydroxy or mercapto provided that R2 and R4 are not both hydrogen, hydroxy or mercapto; when R2 is the group STR4 then R3 is hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, phenyl or substituted phenyl, and R1 and R4, which may be the same or different, are hydrogen, alkyl, alkenyl, hydroxyalkyl, alkoxy, phenyl, substituted phenyl, halogen, trifluoromethyl, thiocyanate, nitro, cyano, amino, carboxy, alkoxycarbonyl, carbamoyl, N-alkylcarbamoyl, N,N-dialkylcarbamoyl, hydroxy or mercapto, provided that R1 and R3 are not both hydrogen and provided that R1 and R4 are not both hydroxy or mercapto; and an inert carrier material therefor.
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(2008/06/13)