Homogeneous and heterogeneous catalytic reduction of amides and related compounds using molecular hydrogen

Substituted methallylmalonic esters (I) were reduced with lithium aluminum hydride to the corresponding 2-methallyl-1,3-propanediols (II). These diols II underwent cyclization on treatment with a mineral acid to the isomeric 2,2-dimethyl-4-substituted-4-hydroxymethyltetrahydrofurans (IV). II and IV were converted to the respective carbamates III and V, which exhibited pharmacological activity. The assigned structures of the cyclic compounds IV were proved by infrared analyses and the following transformations. Ring scission of 2,2-dimethyl-4-allyl-4-hydroxymethyltetrahydrofuran (IVe) with acetic anhydride – pyridine hydrochloride yielded 2-allyl-2-methallyl-1,3-propanediol diacetate (Xe). Catalytic reduction of IVe gave 2,2-dimethyl-4-n-propyl-4-hydroxymethyltetrahydrofuran (IVd). Reductive cleavage of the tosylate VIIIb of 2,2,4-trimethyl-4-hydroxymethyltetrahydrofuran (IVb) with lithium aluminum hydride yielded the known 2,2,4,4-tetramethyltetrahydrofuran (IXb).

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TRYPTAMINES, CARBOLINES, AND RELATED COMPOUNDS: PART IX. THE CYCLIZATION OF SOME NITRO- AND AZIDO-PHENYLPYRIDINES. PYRIDO[1,2-b]INDAZOLE

Canadian Journal of Chemistry ◽

10.1139/v61-332 ◽

1961 ◽

Vol 39 (12) ◽

pp. 2516-2528 ◽

Cited By ~ 33

Author(s):

R. A. Abramovitch ◽

K. A. H. Adams

Keyword(s):

Absorption Spectra ◽

Catalytic Reduction ◽

Nitro Compounds ◽

Ultraviolet Absorption ◽

The Other ◽

Azo Compounds ◽

Minute Amount ◽

Ferrous Oxalate ◽

Related Compounds ◽

General Method

Heating 2-o-nitrophenylpyridine with ferrous oxalate gives rise to pyrido[1,2-b]indazole (III). The evidence for the structure of this compound is discussed. Similarly, heating 2-o-nitrophenylpyridine methiodide and N-oxide with ferrous oxalate gives (III), in each case, demethylation and deoxygenation preceding the cyclization. In the latter case a minute amount of δ-carboline is also formed. Heating pyridine-N-oxides with ferrous oxalate is a potentially general method of effecting deoxygenations of these compounds. Contrary to the results of Smith and Boyer (11), it is found that heating 2-o-azidophenylpyridine also gives rise to (III). On the other hand, the action of heat on 2-o-azidophenyIpyridine-N-oxide gives a mixture of δ-carboline and δ-carboline-py-N-oxide in low yield. The mechanism of the cyclization of the azides and of the reaction taking place on heating nitro-compounds with ferrous oxalate is discussed briefly; the formation of a nitrene intermediate is favored.The catalytic reduction of 2-o-nitrophenylpyridine-N-oxide giving rise to the azoxy-, azo-, and hydrazo-derivatives is described and the ultraviolet absorption spectra of these compounds are discussed. It is concluded the steric inhibition of coplanarity exists in the azoxy- and azo-compounds leading to the lack of effective conjugation across the N=N bond.

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Catalytic Reduction of 4-Benzyloxy-6-methylpyrimidine and Related Compounds.

Chemical and Pharmaceutical Bulletin ◽

10.1248/cpb.7.158 ◽

1959 ◽

Vol 7 (2) ◽

pp. 158-161 ◽

Cited By ~ 9

Author(s):

Hiroshi Yamanaka

Keyword(s):

Catalytic Reduction ◽

Related Compounds

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Surface chemical properties and pore structure of the activated coke and their effects on the denitrification activity of selective catalytic reduction

International Journal of Coal Science & Technology ◽

10.1007/s40789-019-00267-2 ◽

2019 ◽

Vol 6 (4) ◽

pp. 595-602

Author(s):

Wei Xie ◽

Daming Liang ◽

Lanting Li ◽

Sijian Qu ◽

Wu Tao

Keyword(s):

Specific Surface ◽

Pore Size Distribution ◽

Pore Size ◽

Selective Catalytic Reduction ◽

Size Distribution ◽

Catalytic Reduction ◽

Fixed Bed Reactor ◽

Heterogeneous Catalytic ◽

Denitrification Activity ◽

Activated Coke

Abstract In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies. The pore size distribution and BET specific surface area of AC were obtain by data analyzing of N2 adsorption/desorption isotherm at − 196 °C and carbon matrix and surface chemistry of virgin activated coke samples were characterized by acid–base titration and XPS. The process of selective catalytic reduction of activated coke (AC) samples with NH3 as reducing agent was studied in a fixed bed reactor at 150 °C. The result shows that pore size distribution or BET specific surface of activated cokes have not correlation with denitrification activity for SCR. The NO reduction activities of the activated cokes are apparent to increase with their surface oxygen element content and total amount of acidic sites. Obviously there is good linear relationship between the NH3 adsorption capacity and activity for SCR with linear correlation coefficient 0.943. It has been presented that adsorption of NH3 on acidic functional groups in the edge of large polycyclic aromatic ring of activated coke is key rate controlling step in the SCR heterogeneous catalytic reaction.

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