ipso Nitration. XXIII. Reactions of cyclohexadiene adducts from nitration of 4-ethyltoluene in acetic anhydride

1981 ◽  
Vol 59 (15) ◽  
pp. 2314-2327 ◽  
Author(s):  
Alfred Fischer ◽  
George N. Henderson
Keyword(s):  
Sulfuric Acid ◽  
Acetic Anhydride ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Potassium Hydroxide ◽  
Silver Oxide ◽  
Aluminum Hydride ◽  
Trifluoroacetic Anhydride ◽  
Aqueous Methanol

The diastereoisomers of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate (1) and 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate (2) are stereospecifically reduced to the corresponding nitrocyclohexadienols with aluminum hydride. Each dienol is stereospecifically methylated to the corresponding methyl ether with methyl iodide, silver oxide, and potassium hydroxide. Acid-catalysed solvolysis of the acetates 1 and 2 results in the substitution of the acetate moiety by other nucleophiles and these reactions are not stereospecific. The products of rearomatization of dienyl acetates, dienols, and dienyl methyl ethers depend on the acidity and ionizing power of the solvents and are readily explained in terms of reactions involving a nitrocyclohexadienyl cation or acetoxy- (hydroxy-, methoxy-)cyclohexadienyl cation as key intermediates. In the 4-acetoxy-4-alkylcyclohexadienyl cation 1,2-migration of the acetoxyl group is more rapid than alkyl migration, but 1,2-alkyl migration is faster than migration of the hydroxyl or methoxyl groups in the corresponding cations. 1-Ethyl-4-methoxy-4-methylcyclohexa-2,5-dien-1-ol and 4-ethyl-3-nitrotoluene are significant minor products in the solvolysis of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dien-1-ol in aqueous methanol. Nitration of p-ethyltoluene in the presence of sulfuric acid or in trifluoroacetic anhydride gives a mixture of 4-ethyl-2-nitro- and 4-ethyl-3-nitrotoluene in a 2:1 ratio.

STUDIES OF REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES.: XXVIII. THE STRUCTURE OF ISOPROPYLIDENE GLYCEROL

1930 ◽  
Vol 2 (3) ◽  
pp. 214-217 ◽  
Author(s):  
Harold Hibbert ◽  
J. G. Morazain
Keyword(s):  
Methyl Iodide ◽  
Methyl Ether ◽  
Copper Sulphate ◽  
Silver Oxide ◽  
Condensation Product ◽  
Neutral Medium ◽  
Physico Chemical ◽  
Isopropylidene Glycerol

Isopropylidene glycerol, prepared in neutral medium by the action of anhydrous copper sulphate as condensing agent, was methylated with silver oxide and methyl iodide; the product yielded only glycerol α-methyl ether on hydrolysis, thus proving the absence of any six-membered ketal in the condensation product of glycerol and acetone.The properties of both glycerol α- and β-methyl ethers have been carefully redetermined.A table of the isomeric acetals and ketals summarising their physico-chemical constants is given, in view of their usefulness as "type compounds" in investigations relating to fats, carbohydrates and polysaccharides.

METHYLATION OF SUGAR DITHIOACETALS: IV. D-XYLOSE DIETHYL DITHIOACETAL

1962 ◽  
Vol 40 (10) ◽  
pp. 1899-1902 ◽  
Author(s):  
G. G. S. Dutton ◽  
Y. Tanaka
Keyword(s):  
Methyl Iodide ◽  
Methyl Ether ◽  
Silver Oxide ◽  
Partial Methylation ◽  
Tetrahydrofuran Solution

Partial methylation of D-xylose diethyl dithioacetal in tetrahydrofuran with methyl iodide and silver oxide yielded 2-, 3-, and 5-O-methyl-D-xyloses in the ratio of 20:10:1. The poly-O-methylated components were not examined. The 2-O-methyl-D-xylose was identified as the crystalline sugar and the 3-O-methyl ether as the phenylosazone and p-bromophenylosazone. An alternative preparation of the dithioacetal in tetrahydrofuran solution is described.

Ipso nitration. XIX. Formation of cyclohexadiene adducts from nitration of 4-ethyltoluene and 1,4-diethylbenzene in nitric acid and acetic anhydride

1978 ◽  
Vol 31 (6) ◽  
pp. 1241 ◽  
Author(s):  
A Fischer ◽  
GN Henderson ◽  
RJ Thompson
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Trifluoroacetic Acid ◽  
Trifluoroacetic Anhydride ◽  
Phenyl Acetate ◽  
Aqueous Methanol ◽  
Methyl Phenyl

Nitration of 4-ethyltoluene in acetic anhydride at -20° gives the diastereoisomers of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate and of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate. Similar nitration of 1,4-diethylbenzene gives the diastereoisomers of 1,4-diethyl-4-nitro-cyclohexa-2,5-dienyl acetate. Rearomatization of the adducts of p-ethyltoluene in trifluoroacetic acid-trifluoroacetic anhydride gives 4-ethyl-2-nitrotoluene from the 1-ethyl-4-methyl-4- nitro isomers and 4-ethyl-3-nitrotoluene from the 4-ethyl-1-methyl-4-nitro isomers. In aqueous methanol 2-ethyl- 5-methylphenyl acetate is obtained from the 1-ethyl-4-methyl-4-nitro isomers and 5-ethyl-2- methyl-phenyl acetate from the 4-ethyl-1-methyl-4-nitro isomers.

Chemistry of the aminochromes. Part XI. Studies on 2-methylaminochromes

1969 ◽  
Vol 47 (11) ◽  
pp. 2003-2007 ◽  
Author(s):  
O. Hutzinger ◽  
R. A. Heacock
Keyword(s):  
Acetic Anhydride ◽  
Sodium Borohydride ◽  
Silver Oxide ◽  
Potassium Iodate ◽  
Sodium Hydrosulfite

2-Methyladrenochrome and 1-ethyl-2-methylnoradrenochrome have been prepared by oxidation of 3,4-dihydroxyephedrine and 3,4-dihydroxyhomoephedrine with silver oxide. The corresponding 7-iodoaminochromes were obtained when the oxidations were carried out with potassium iodate. The expected 3,5,6-triacetoxyindoles were formed by treatment of these aminochromes with acetic anhydride and pyridine and the corresponding 5,6-dihydroxyindoles (isolated as their diacetyl derivatives) were obtained by reduction of the aminochromes with sodium borohydride or sodium hydrosulfite. An improved procedure for the synthesis of 3,4-dihydroxyephedrine (α-methyladrenaline) is also described.

Lithiation of bridgehead positions in 3,6-bridged piperazine-2,5-diones

1982 ◽  
Vol 35 (11) ◽  
pp. 2289 ◽  
Author(s):  
FW Eastwood ◽  
D Gunawardana ◽  
GT Wernert
Keyword(s):  
Carbonyl Group ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Sodium Methoxide ◽  
Inductive Effect ◽  
Amide Nitrogen

2,5-Dimethyl-2,5 diazabicyclo[2,2,2]octane-3,6-dione can be lithiated at the 1,4 (bridgehead) positions with 2 equiv. of t-butyllithium at -78� and deuterated with D2O (Do, 11.2; Dl, 56.1 ; D2, 30.1%). With butyllithium and methyl iodide the 1,2,5-trimethyl and 1,2,4,5-tetramethyl derivatives are obtained. Treatment of dimethyl 2,6-diaminoheptanedioate dihydrochloride with sodium methoxide in boiling butanol gives 6,8-diazabicyclo[3,2,2]nonane-7,9-dione in 62% yield. N-Methylation of this compound yields 6,8-dimethyl-6,8-diazabicyclo[3,2,2]nonane-7,9-dione which can similarly be lithiated at the 1,5 (bridgehead) positions and deuterated with D2O (Do, 5.6; Dl, 70.8; D2, 23.6%). Lithiation with butyllithium and reaction with methyl iodide, benzyl iodide or bromomethyl methyl ether gives mono-and di-alkylated products at the 1,5-positions. The ability to lithiate the bridgehead positions in these compounds is attributed primarily to a combination of the inductive effect of the carbonyl group and dipole stabilization by the amide nitrogen.

Acetylation and Formylation of 3-Ferrocenylpyrroles

1999 ◽  
Vol 64 (1) ◽  
pp. 99-106
Author(s):  
Battsengel Gotov ◽  
Štefan Toma ◽  
Eva Solčániová
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Aluminum Chloride ◽  
Acetyl Chloride ◽  
Trifluoroacetic Anhydride ◽  
Acid Mixture ◽  
Chloride Method

Acetylations of 3-ferrocenyl-1-methylpyrrole as well as 3-cyano-4-ferrocenylpyrrole and 3-cyano-4-ferrocenyl-1-methylpyrrole were performed. The course of the acylation is highly dependent on the acylation agent, that is acetyl chloride/aluminum chloride (method A), trifluoroacetic anhydride-acetic acid mixture (method B) or acetic anhydride/Sc(OTf)3 (method C). Method A gives the acetylation on ferrocene moiety, method B affords the trifluoroacetylation on pyrrole moiety and method C affords pyrrole moiety acetylation. Vielsmeier-Haack formylation gives the products of substitution on pyrrole moiety.

THE REACTION OF DIETHYL AZODICARBOXYLATE WITH DIHYDROGELSEMINE

1955 ◽  
Vol 33 (4) ◽  
pp. 604-609 ◽  
Author(s):  
Thelma Habgood ◽  
Léo Marion
Keyword(s):  
Infrared Spectrum ◽  
Methyl Ether ◽  
Sodium Borohydride ◽  
Lithium Aluminum Hydride ◽  
Chromic Acid ◽  
Aluminum Hydride ◽  
Membered Ring ◽  
Lithium Aluminum ◽  
Diethyl Azodicarboxylate ◽  
Methylene Group

Dihydrogelsemine reacts with diethyl azodicarboxylate yielding a carbinolamine which forms a methyl ether. Both this ether and the carbinolamine base can be oxidized by chromic acid to the same neutral lactam. That there has been no rearrangement of the carbon skeleton during these reactions is shown by reduction of the methyl ether of the carbinolamine with sodium borohydride to dihydrogelsemine and by reduction of the lactam with lithium aluminum hydride to tetrahydrodesoxygelsemine. It is concluded that both dihydrogelsemine and gelsemine contain a methylene group adjacent to N(b), and from the infrared spectrum of the lactam of dihydrogelsemine, N(b) appears to be part of a five-membered ring.

METHYLATION OF SUGAR MERCAPTALS: II. L-ARABINOSE DIETHYL MERCAPTAL

1961 ◽  
Vol 39 (9) ◽  
pp. 1797-1800 ◽  
Author(s):  
G. G. S. Dutton ◽  
Y. Tanaka
Keyword(s):  
Methyl Iodide ◽  
Silver Oxide

Methylation of L-arabinose diethyl mercaptal in tetrahydrofuran with methyl iodide and silver oxide yielded mainly 2-O-methyl-L-arabinose and a trace of 5-O-methyl-L-arabinose. The identity of the major component was inferred by its behavior on electrophoresis and confirmed by the preparation of the crystalline amide. The polymethylated components were not examined. 2-O-Methyl-L-arabono-γ-lactone, previously known as a sirup, has now been obtained crystalline.

Sign in / Sign up

Export Citation Format

Share Document