Studies on condensed pyrazoles: Synthesis of new methyl and amino pyrazolo[1,5-a]pyrimidines and of pyrazolo[5,1-c][1,2,4]triazines

1989 ◽  
Vol 54 (4) ◽  
pp. 1082-1091 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Nadia Hassen Taha ◽  
Fatma Abdel Maksoud Abd El All ◽  
Ramadan Maawad Abdel-Motaleb ◽  
Fivian Farouk Mahmoud
Keyword(s):  
Acetic Acid ◽  
Sulphuric Acid ◽  
Acid Mixture ◽  
H Nmr ◽  
Active Methylene

A variety of 3-arylazo 5-amino and 7-aminopyrazolo[1,5-a]pyrimidines were obtained via reacting Ia-Id with cinnamonitriles. The structure of products was confirmed via 1H NMR. Both 5-amino- and 7-amino-3-arylazo pyrazolo[1,5-a]pyrimidines reacted, with protons in acetic acid-sulphuric acid mixture to yield the corresponding 3-unsubstituted acetylaminopyrazolo[1,5-a]pyrimidines. Diazotized Ia and Ib coupled with a variety of active methylene reagents to yield pyrazolo[5,1-c][1,2,4]triazines.

Pyrimidine Derivatives and Related Compounds, VII Synthesis of Some New Pyrazolo [1,5-a] -S-triazines, Pyrazolo [3,4-c] -as-triazines, Pyrazolo [1,5-a] pyrimidines and Pyrazolo [3,4-b] pyrones

1977 ◽  
Vol 32 (4) ◽  
pp. 430-433 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Ezzat Mohamed Zayed ◽  
Ezzat Mohamed Kandeel ◽  
Sherif Mahmoud Fahmy
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Sodium Ethoxide ◽  
Ethyl Acrylate ◽  
The Other ◽  
Acid Mixture ◽  
Pyrimidine Derivatives ◽  
Triazine Derivative ◽  
Related Compounds

3-Amino-4-phenylhydrazono-2-pyrazolin-5-one (1) reacts with isothiocyanate to yield the corresponding pyrazolylthiourea derivatives (2 a-c). Whereas 2 a reacted with hydrazines to yield the pyrazolylamino-1,2,4-triazoles (3 a, b), it cyclised into the pyrazolo-[3,4-e]-as-triazine derivative (4) upon treatment with concentrated sulphuric acid. On the other hand, the pyrazolo[1,5-c]-S-triazine derivative (5) was formed from reaction of 2a with ethanolic sodium ethoxide.3-Amino-2-pyrazolin-5-one (8) reacted with ethyl acrylate to yield a mixture of the 4-dialkylated derivative (9) and the pyrazolo[3,4-b]pyrone (11). Compound 11 could be converted into the corresponding pyrazolo[3,4-b]pyrones (12) and (13) by the action of acetic acid hydrochloric acid mixture and of concentrated sulphuric acid, respectively.

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

Acetic acid mediated regioselective synthesis of 2,4,5-trisubstituted thiazoles by a domino multicomponent reaction

2019 ◽  
Vol 43 (22) ◽  
pp. 8644-8650 ◽  
Author(s):  
Mohit Saroha ◽  
Jitender M. Khurana
Keyword(s):  
Acetic Acid ◽  
Multicomponent Reaction ◽  
Regioselective Synthesis ◽  
Domino Reaction ◽  
Thiazole Derivatives ◽  
Active Methylene

Acetic acid mediated regioselective synthesis of novel 2,4,5-trisubstituted thiazole derivatives has been reported by a domino reaction of thiosemicarbazide and aldehydes/ketones/isatin, to generate thiosemicarbazones (in situ) followed by addition of arylglyoxal and active methylene/activated C–H acids/pyrazole/indole in ethanol at 80 °C.

Synthesis of amino acid derivatives of indole-3-acetic acid

2005 ◽  
Vol 2005 (10) ◽  
pp. 640-642 ◽  
Author(s):  
Ying Liu ◽  
Liang Zhao ◽  
Liang Liu ◽  
Lin-Yi Wei ◽  
Lu-Hua Lai
Keyword(s):  
Acetic Acid ◽  
Amino Acid ◽  
Amino Acid Derivatives ◽  
H Nmr ◽  
Derivatives Of ◽  
Indole 3 Acetic Acid

Amino acid derivatives of a modified indole-3-acetic acid have been synthesised. Fourteen new dipeptide-like compounds 3–4 were obtained and their structures were elucidated based on the IR, 1H NMR, MS spectra.

HYDROLYSIS OF CELLULOSE ACETATE SULPHATE IN ACETONE

1954 ◽  
Vol 32 (9) ◽  
pp. 815-822 ◽  
Author(s):  
Karl Keirstead ◽  
John Myers
Keyword(s):  
Acetic Acid ◽  
Cellulose Acetate ◽  
Sulphuric Acid ◽  
Potentiometric Titration ◽  
Titration Method ◽  
Acetate Ester ◽  
Hydrolysis Of Cellulose ◽  
Potentiometric Titration Method ◽  
Hydrolysis Of

When cellulose acetate sulphate is dissolved in acetone the hydrolysis of the sulphate ester is rapid compared with that of the acetate ester. In 70% acetone the relative rates are reversed. Hydrolysis of the sulphate ester in acetone is greatly affected by the temperature. At 25 °C. or greater the hydrolysis is complete after 24 hr. A potentiometric titration method has been developed for the estimation of sulphuric acid in the presence of smaller amounts of acetic acid.

scholarly journals Highly Efficient Biosynthesis of Indole-3-acetic acid by Enterobacter xiangfangensis BHW6

2020 ◽  
Author(s):  
Bi-Xian Zhang ◽  
Ying-Ying Wang ◽  
Xiaomei Hu
Keyword(s):  
Acetic Acid ◽  
Economic Value ◽  
Pyruvate Decarboxylase ◽  
Genomic Analysis ◽  
Rrna Gene ◽  
H Nmr ◽  
Gene Coding ◽  
Key Enzyme ◽  
Indole 3 Acetic Acid ◽  
Iaa Biosynthesis

Abstract Background: Indole-3-acetic acid (IAA) plays an important role in the growth and development of plants. Various bacteria in the rhizosphere are capable to produce IAA that acts as a signaling molecule for the communication between plants and microbes to promote the plant growth. Due to the low IAA content and various interfering analogs, it is difficult to detect and isolate IAA from microbial secondary metabolites. Results: A predominant strain with a remarkable capability to secrete IAA was identified as Enterobacter xiangfangensis BHW6 based on 16S rRNA gene sequence, the determination of average nucleotide identity (ANI) and digital DDH (dDDH). The maximum IAA content (134-1129 μg/mL) was found with the addition of 0.2-15 g/L of L-tryptophan at pH 5 for 6 days, which was 4-40 fold higher than that in the absence of L-tryptophan. The highest yield of IAA was obtained at the stationary phase of bacterial growth. An acidic culture medium was preferred for the IAA biosynthesis of the strain. The strain was tolerant and stable to produce IAA in the presence 2.5%-5% (w/v) of NaCl. IAA was then isolated through column chromatography with a mobile phase of hexane/ethyl acetate (1/2, v/v) and characterized by 1H Nuclear Magnetic Resonance (1H NMR). Conclusions: A remarkable IAA production was obtained from E. xiangfangensis BHW6 that was tryptophan–dependent. According to genomic analysis, the ipdC gene coding for the key enzyme (indole-3-pyruvate decarboxylase) was identified indicating that IAA biosynthesis was mainly through the indole-3-pyruvia acid (IPyA) pathway, which was further confirmed by intermediate assay. E. xiangfangensis BHW6 with an important economic value has great prospect in agricultural and industrial application.

scholarly journals Synthesis and Characterization of Some Novel Oxazine, Thiazine and Pyrazol Derivatives

2016 ◽  
Vol 13 (2) ◽  
pp. 244-252
Author(s):  
Baghdad Science Journal
Keyword(s):  
Acetic Acid ◽  
Ir Spectra ◽  
Glacial Acetic Acid ◽  
Basic Medium ◽  
Synthesis And Characterization ◽  
Pyrazole Derivatives ◽  
Phenyl Hydrazine ◽  
H Nmr ◽  
Ft Ir

In this paper, some chalcone derivatives (C1, C2) were synthesized based on the reaction of equal amount of substituted acetophenone and substituted banzaldehyde in basic medium. Oxazine and thiazine derivatives were prepared from the reaction of chalcones (C1-C2) with urea and thiourea respectively in a basic medium. Pyrazole derivatives were prepared based on the reaction of chalcones with hydrazine mono hydrate or phenyl hydrazine in the presence of glacial acetic acid as a catalyst. The new synthesized compounds were identified using various physical techniques like1 H-NMR and FT-IR spectra.

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