The bromination and chlorination of 2,3-dialkylindoles. Isolation of 3-bromo- and 3-chloro-2,3-dialkylindolenines and acid catalyzed conversion to 3-methoxyindolenines

1980 ◽  
Vol 58 (8) ◽  
pp. 808-814 ◽  
Author(s):  
Gary I. Dmitrienko ◽  
Edward A. Gross ◽  
Susan F. Vice
Keyword(s):  
Acetic Acid ◽  
Good Yield ◽  
Room Temperature ◽  
Chemical Properties ◽  
Nitrogen Atmosphere ◽  
Crystalline Solid ◽  
Tert Butyl ◽  
Acidic Conditions ◽  
Acid Catalyzed

The bromination of 2,3-dimethylindole in acetic acid followed by hydrolysis has been shown to yield the known dimer 16 of 3-hydroxy-2,3-dimethylindolenine 15 and not 3-hydroxymethyl-2-methylindole 12 as reported previously by others. Bromination of 2,3-dimethylindole in the presence of triethylamine has yielded 3-bromo-2,3-dimethylindolenine 17 as a crystalline solid which is stable at room temperature in a nitrogen atmosphere in the presence of triethylamine but decomposes vigorously in the absence of base. Under mildly acidic conditions 17 reacts rapidly with methanol to yield 3-methoxy-2,3-dimethylindolenine 3 in good yield. With tert-butyl hypochlorite in the presence of triethylamine, 2,3-dimethylindole gives 3-chloro-2,3-dimethylindolenine 2 which has chemical properties similar to 17 reacting readily with methanol to give 3. Similarly tetrahydrocarbazole was converted to the analogous chloroindolenine 5 and bromoindolenine 18 both of which readily underwent methanolysis to give 6 in good yield. A mechanism for the acid catalyzed methanolysis of 3-chloro- and 3-bromoindolenines is proposed.

Nitration of 4-tert-butyl-o-xylene in acetic anhydride. Formation and rearomatization of adducts

1978 ◽  
Vol 56 (2) ◽  
pp. 258-266 ◽  
Author(s):  
Alfred Fischer ◽  
Khay Chuan Teo
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Nitro Group ◽  
Tert Butyl ◽  
Acidic Conditions ◽  
Group Migration

Nitration of 4-tert-butyl-1,2-dimethylbenzene in acetic anhydride gives trans-1-tert-butyl-3,4-dimethyl-4-nitro-1,4-dihydrophenyl acetate (6), trans-1-tert-butyl-3,4-dimethyl-4-nitro-1,4-dihydrophenol, 2-tert-butyl-4,5-dimethylphenyl acetate, 5-tert-butyl-2-methylbenzaldehyde, 4-tert-buty]-1,2-dimethyl-5-nitrobenzene, and 4-tert-butyl-1,2-dimethyl-6-nitrobenzene. 2-tert-Butyl-4,5-dimethylphenyl acetate and 3,4-dimethylphenyl acetate are the major products of solvolysis of 6 in moist acetic acid. Both of these compounds are likely formed via the cation generated by ionization of the nitro group. Under more acidic conditions 5-tert-butyl-2-methylbenzaldehyde and 4-tert-butyl-1,2-dimethyl-6-nitrobenzene, formed via the cation generated by acid-catalysed loss of acetate, become dominant, the balance between these products being controlled by the basicity of the solvent. More basic solvents deprotonate the cation to a triene, a key step in the formation of the aldehyde, at a competitive rate with the nitro group migration.

Record-Breaking Steric Crowding in Trialkylamines Prepared by Oxidative Ring Opening

Synthesis ◽  
2020 ◽  
Vol 52 (24) ◽  
pp. 3801-3810
Author(s):  
Klaus Banert ◽  
Manuel Heck ◽  
Andreas Ihle ◽  
Erik Michael ◽  
Richard Weber
Keyword(s):  
Ring Opening ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Model Compound ◽  
Ring Cleavage ◽  
Open Chain ◽  
Tert Butyl ◽  
Steric Crowding ◽  
Acid Catalyzed ◽  
Subsequent Acid

AbstractEpoxidation of olefinic heterocyclic amines and subsequent acid-catalyzed hydrolysis or alternatively the direct dihydroxylation with the help of osmium tetroxide led to diols, which underwent ring cleavage in the presence of lead tetraacetate to give 3-isopropyl-2,2,4,4-tetramethyl-3-azahexanedial and 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial. Whereas the former dialdehyde is a highly unstable model compound because of a rapid intramolecular aldol reaction, the latter product proves to be isolable at room temperature. Furthermore, this compound is the first open-chain tri-tert-alkylamine establishing in a new record of steric crowding in tertiary amines. Strong tendencies to a Hofmann-like elimination reaction or to ring-closing reactions were observed when the aldehyde units of 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial were transformed into other functionalities, since both types of reactions led to a significantly decrease of the steric stress.

Transmission infrared study of acid-catalyzed sol-gel silica coatings during room ambient drying

1992 ◽  
Vol 7 (8) ◽  
pp. 2230-2239 ◽  
Author(s):  
T.M. Parrill
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Infrared Spectra ◽  
Spin Coating ◽  
Room Temperature ◽  
Sol Gel ◽  
Infrared Study ◽  
Silica Coatings ◽  
Acidic Conditions ◽  
Acid Catalyzed

Sol-gel solutions prepared from tetraethylorthosilicate (TEOS) hydrolyzed in acidic conditions were used to make thin films on Si wafers via spin coating. Solutions with H2O/TEOS ratios of 2, 5, and 10 were prepared and aged at room temperature in sealed containers for times ranging from <2.5 h to 1 month. Transmission Fourier transform infrared spectra acquired around 1 min after spinning showed peaks characteristic of both SiO2 and SiOH. Additional features at ≍580, 1093, and 1130 cm−1 were observed and possible origins are discussed. Peaks at ≍580 and 1130 cm−1, which increased in intensity with solution age time, are attributed to cyclic Si–O, e.g., 4-member rings. When films were exposed to room air, ring concentration decreased significantly within 30 min. Rings were stable for hours, however, when films were kept in N2. The feature at 1093 cm−1, most sensitive to H2O/TEOS, is attributed to residual Si–O–C.

Effect of Fish Scales Gelatin and Mixing Ratio on Chemical and Mechanical Characteristics of Gelatin/Chitosan Films

2017 ◽  
Vol 866 ◽  
pp. 8-11 ◽  
Author(s):  
Nisakorn Nuamsrinuan ◽  
Noppadon Suttisiri ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
Kittisakchai Naemchanthara
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
White Perch ◽  
Chemical Properties ◽  
Chitosan Solution ◽  
Fish Scale ◽  
Fish Scales ◽  
Mixing Ratios ◽  
Gelatin Films ◽  
Chitosan Films

The objective of this work was to compare the chemical properties and mechanical properties (strength and elongation) of gelatin/chitosan (G/Ch) films. The effect of several fish scales such as white perch, java barb, red tilapia and nile tilapia scales and mixing ratios of G/Ch composite was investigated. Several fish scales were cleaned and treated with 1.0 M NaOH and 0.8 M acetic acid at room temperature for 120 min to remove fat. Gelatins were extracted from fish scales using the distilled water at 70°C for 120 min. Chitosan solution was prepared with 1% (w/v) chitosan in 1% (v/v) acetic acid, stirred at room temperature. After that, the G/Ch films were prepared by mixing the fish scale gelatins and chitosan with different ratios and then dried at 70°C. The results showed that the FT-IR of G/Ch films revealed the function groups of both gelatin and chitosan. The gelatin films showed peaks amide A (3219-3315 cm-1), alkane (2930-2958 cm1, 1400 -1479 cm-1and 675-1000 cm-1), amide I (1630-1655 cm-1), amide II (1520-1560 cm-1), amide III (1220-1335 cm-1), and ether (1020-1035 cm-1). The chitosan films showed peaks amide II (1559 cm-1), alkane (1404 cm-1) and ether (1022 cm-1). The tensile strength results of G/Ch films increased and elongation of G/Ch films decreased with increasing the amount of chitosan.

An improved synthesis of 1,3-dihydro-1-methyl-5-phenyl-2H-pyrido[3,4-e]-1,4-diazepin-2-one via ortho-directed lithiation of 3-tert-butyl and 3-tert-butoxycarbonylaminopyridine

1987 ◽  
Vol 65 (6) ◽  
pp. 1158-1161 ◽  
Author(s):  
Charles Y. Fiakpui ◽  
Edward E. Knaus
Keyword(s):  
Acid Hydrolysis ◽  
Good Yield ◽  
Tert Butyl ◽  
Acid Catalyzed ◽  
Glycine Derivatives

The ortho-directed lithiation of 3-tert-butyl- or 3-tert-butoxycarbonylaminopyridines (3) with alkyllithiums and reaction with N,N-diethylbenzamide followed by acid hydrolysis gave 3-amino-4-benzoylpyridine (6) in good yield. Reaction of BTBO with the glycine derivatives 7a, b and then reaction with 6 afforded 3-alkoxycarbonylaminomethylcarbonylamino-4-benzoylpyridines 8a, b. Acid-catalyzed hydrolysis and cyclization of 8a, b yielded 9, which on methylation gave 1,3-dihydro-1-methyl-5-phenyl-2H-pyrido[3,4-e]-1,4-diazepin-2-one (10) in 36% overall yield from 3a.

scholarly journals Green Synthesis of Substituted dihydropyrimidin-2(1H)-one by using Zinc Chloride /acetic acid Catalytic System

2020 ◽  
Vol 01 ◽  
Author(s):  
Bapu R Thorat ◽  
Ankita Gurav ◽  
Bharat Dalvi ◽  
Ashwini Sawant ◽  
Vikas Lokhande ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Catalytic System ◽  
Zinc Chloride ◽  
Good Yield ◽  
Room Temperature ◽  
Biginelli Reaction ◽  
Biologically Active ◽  
Dicarbonyl Compounds ◽  
Acetyl Acetone ◽  
Chloride Catalyst

Background: Biginelli reaction is the most well-known and widely studied multicomponent reaction used for the direct synthesis of many biologically active 3,4-dihydropyrimidin-2(1H)-ones and their derivatives by reacting a β-keto ester/1,3- dicarbonyl compound, an aldehyde, and urea. It was catalyzed by different Bronsted and Lewis acids. Methods: The catalytic effect of different metal chloride such as sodium, potassium, magnesium, stannous, ferric, manganese, cupric, nickel, cobalt, and zinc chlorides in absence and presence of acetic acid were studied. Results: The zinc, ferric, cupric, and cobalt chlorides were found to be more effective catalysts for Biginelli reaction at room temperature. The yield of reaction was increases with temperature for all catalytic system. Acetophenone, cyclohexanone, acetyl acetone, and different β-ketoesters forming tetrahedropyrimidine in moderate to good yield by using zinc chloride catalyst at room temperature in acetic acid. The efficiency of the catalyst was studied by treating different substituted aldehydes with 1,3-dicarbonyl compounds and urea at room temperature Results: The zinc, ferric, cupric, and cobalt chlorides were found to be more effective catalysts for Biginelli reaction at room temperature. The yield of reaction was increases with temperature for all catalytic system. Acetophenone, cyclohexanone, acetyl acetone, and different β-ketoesters forming tetrahedropyrimidine in moderate to good yield by using zinc chloride catalyst at room temperature in acetic acid. The efficiency of the catalyst was studied by treating different substituted aldehydes with 1,3-dicarbonyl compounds and urea at room temperature. Conclusion: The zinc chloride in acetic acid found to be effective greener catalyst system for Biginelli reaction.

Naturally Occurring Organic Acid-catalyzed Facile Diastereoselective Synthesis of Biologically Active (E)-3-(arylimino)indolin-2-one Derivatives in Water at Room Temperature

2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  
Keyword(s):  
Room Temperature ◽  
Biologically Active ◽  
Environmentally Benign ◽  
Diastereoselective Synthesis ◽  
Substituted Anilines ◽  
Reaction Conditions ◽  
Naturally Occurring ◽  
Acid Catalyzed ◽  
Reaction Media ◽  
Column Chromatographic

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.

15N NMR studies provide insights into physico-chemical properties of room-temperature ionic liquids

2021 ◽  
Author(s):  
Christoph Wiedemann ◽  
David Fushman ◽  
Frank Bordusa
Keyword(s):  
Ionic Liquids ◽  
Room Temperature ◽  
Chemical Properties ◽  
Room Temperature Ionic Liquids ◽  
15N Nmr ◽  
Nmr Studies ◽  
Physico Chemical ◽  
Alternative Solvents

Ionic liquids (ILs) have gained a lot of attention as alternative solvents in many fields of science in the last two decades. It is known that the type of anion...

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