- Synthesis method of N-hydroxyethyl-5-amino-1H pyrazole
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The invention discloses a synthesis method of N-hydroxyethyl-5-amino-1H pyrazole. The synthesis method comprises the following steps: by taking N, N-dimethylformamide as a raw material, carrying out one-pot reaction on the N, N-dimethylformamide, dimethyl sulfate and cyanoacetic acid R ester to prepare 2-cyano-3-(dimethylamino) acrylic acid R ester; carrying out cyclization and hydrolysis on the 2-cyano-3-(dimethylamino) acrylic acid R ester and beta-hydroxyethylhydrazine to prepare N-hydroxyethyl-5-amino-1H pyrazole-4-formic acid; and carrying out decarboxylation on N-hydroxyethyl-5-amino-1H pyrazole-4-formic acid, so as to prepare N-hydroxyethyl-5-amino-1H pyrazole, wherein R is an alkane group below C4. The synthesis method provided by the invention has the advantages of strong operability, high economic benefit and high yield.
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Paragraph 0023; 0028-0030; 0035-0037; 0042-0044; 0049; ...
(2021/07/21)
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- Deacetylcolchicine deriv.
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Provided are 4-modified colchicine compounds and medicines using the same. Specifically provided are colchicine derivatives represented by general formula (1), salts thereof, and solvates of the same. In general formula (1), R1 is a halogen atom, a hydroxyl group, a nitro group, an amino group, or a mono-, di- or tri-fluoromethyl group; R2, R3 and R4 are each a methoxy group or a hydroxyl group, or alternatively R2 and R3, or R3 and R4 together represent a methylenedioxy group; R5 and R6 may be the same or different and are each a hydrogen atom, a C1-6 alkyl group, an arylalkyl group, a C2-6 alkenyl group, -COR7, -COOR8, -SO2R9, -CONR10R11, or -CSNR12R13, or alternatively R5 and R6 together with the nitrogen atom to which R5 and R6 are bonded may form a three- to seven-membered cyclic amino group; R7 is a C1-6 alkyl group or the like; R8 is a C1-6 alkyl group or the like; R9 is a C1-6 alkyl group or the like; R10 and R11 may be the same or different and are each a hydrogen atom, a C1-6 alkyl group, or the like; and R12 and R13 may be the same or different and are each a hydrogen atom, an alkyl group, or the like.
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Paragraph 0468
(2016/10/08)
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- Cyanoacetaldehyde - New Synthetic Applications of an Old Compound Syntheses with Nitriles, XCI
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Various reactions of cyanoacetaldehyde (1), freshly prepared by ozonization of (E)-1,4-dicyano-2-butene or allylcyanide, are described.Thus, conversion of 1 with anilines gave β-phenylaminoacrylonitriles 2a-e.Reaction of 1 with hydrazines led to the corresponding hydrazones 3a-e, which could be cyclized under alkaline conditions to 5-aminopyrazoles 4a-d.An aldol-type condensation product 5a could be obtained by reaction of 1 with sodiumphenoxide.Treatment of 1 with dimethylformamide-dimethylacetal led to the formation of (E)-3-dimethylamino-2-formylpropenenitrile (6), a very useful synthon in synthetic chemistry.For the determination of the structure of 6 the method of steady state diffferential NOEs was used.Reaction of 6 with hydrazines gave 1-substituted-4-cyanopyrazoles 7a-k. Keywords.Cyanoacetaldehyde; Hydrazones; Cyanopyrazoles; Aminopyrazoles.
- Jachak, Madhukar,Kriessmann, Ulrike,Mittelbach, Martin,Junek, Hans
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p. 199 - 208
(2007/10/02)
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