Hydrolysis of Substituted Diphenylacetaldehyde Ethylene Glycol Cyclic Acetals in Aqueous Hydrochloric Acid

1973 ◽  
Vol 51 (22) ◽  
pp. 3820-3825 ◽  
Author(s):  
Bruce L. Jensen ◽  
Raymond E. Counsell
Keyword(s):  
Hydrochloric Acid ◽  
Ethylene Glycol ◽  
Product Distribution ◽  
Electronic Effects ◽  
Cyclic Acetals ◽  
Aqueous Hydrochloric Acid ◽  
Methoxy Groups ◽  
Hydrolysis Of

The chemistry of DDT and DDD derivatives was explored by studying the steric and electronic effects on the hydrolysis of a variety of substituted diphenylacetaldehyde ethylene glycol cyclic acetals. This investigation demonstrated that ortho substituents, p-nitro, and p-methoxy groups affect the product distribution in different ways. The mechanistic details of this work are discussed.

SYNTHESIS OF α-AMINO ACIDS FROM ETHYL CYANOACETATE

1952 ◽  
Vol 30 (8) ◽  
pp. 592-597 ◽  
Author(s):  
Paul E. Gagnon ◽  
Guy Nadeau ◽  
Raymond Côté
Keyword(s):  
Amino Acids ◽  
Hydrochloric Acid ◽  
Alkaline Medium ◽  
Potassium Carbonate ◽  
Ethyl Cyanoacetate ◽  
Similar Treatment ◽  
Aqueous Hydrochloric Acid ◽  
Hydrolysis Of ◽  
Curtius Degradation

Monosubstituted cyanoacetic esters, obtained by condensation of 1-bromo-3(s)-phenoxypropanes (s = o-Cl, o-Br, o-I, o-, m-, and p-NO2) or 1-bromo-2(s)-phenoxyethanes (s = o-Cl, o-Br, o-I, and m-NO2) with ethyl cyanoacetate by means of potassium carbonate, were transformed through a Curtius degradation into cyanoacetisocyanates. These compounds by hydrolysis in acid or alkaline medium gave α-amino acids. However, hydrolysis of the corresponding carbobenzyloxy- or carbethoxyaminonitriles afforded better yields. The carbobenzyloxyaminonitriles were more readily hydrolyzed in aqueous hydrochloric acid than the carbethoxyaminonitriles. Moreover, the mild action of dry hydrochloric acid on the carbobenzyloxy derivatives yielded the α-amino acids readily whereas similar treatment of the carbethoxy derivatives gave the carbethoxyamino acids.

The Hydrolysis of Some N-Acylaspartic and N-Acylglutamic Monoamides in Dilute Mineral Acid

1975 ◽  
Vol 53 (11) ◽  
pp. 1137-1144 ◽  
Author(s):  
M. Ali ◽  
J. B. Capindale
Keyword(s):  
Hydrochloric Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Rate Constants ◽  
Mineral Acid ◽  
First Order ◽  
Order Rate ◽  
Succinamic Acid ◽  
Aqueous Hydrochloric Acid ◽  
Hydrolysis Of

The release of ammonia by hydrolysis of N-benzoyl-L-asparagine, glycyl-DL-asparagine, L-asparagine, and succinamic acid, and of aniline from N-benzoyl-L-glutamic-α-anilide, N-benzoyl-L-aspartic-α-anilide, L-aspartic-α-anilide, and the monoanilides of succinic and glutaric acids is first-order with respect to substrate in dilute (0.4–0.03 M) aqueous hydrochloric acid at 100 °C. The first-order rate constants (kobs) for these reactions can be expressed as kobs = kintra + k2[H+]. The above hydrolyses are used as models for developing a tentative mechanism to account for the selective release of aspartic acid from proteins under these conditions. The data are also used to suggest reasons why glutamic acid is not released with equal facility.

Cyclocondensations of Substituted Thiosemicarbazides with 2-Bromo- 1,2-diphenylethan-1-one

2013 ◽  
Vol 68 (7) ◽  
pp. 823-830 ◽  
Author(s):  
Wolf-Diethard Pfeiffer ◽  
Helmut Gille ◽  
Ehrenfried Bulka ◽  
Ashot Saghyan ◽  
Peter Langer
Keyword(s):  
Hydrochloric Acid ◽  
Product Distribution ◽  
Substitution Pattern

The cyclocondensation of 4-methylthiosemicarbazide with 2-bromo-1,2-diphenylethan-1-one in ethanol afforded isomeric 2-methylamino-5,6-diphenyl-6H-3,4-thiadiazine and 2-hydrazono-3- methyl-4,5-diphenyl-2,3-dihydro-1,3-thiazole. A pyrazole was obtained by cyclocondensation and subsequent desulfurization of the thiadiazine when the reaction was carried out in concentrated hydrochloric acid. A chemical proof of the structures has been provided. The product distribution of the cyclizations strongly depends on the substitution pattern of the starting materials, and the cyclizations of methylthiosemicarbazide with 2-bromo-1,2-diphenylethan-1-one behaved considerably different from that of the analogous reactions of α-bromoacetophenone.

A 35Cl magnetic resonance study of chloride exchange on indium(III) and thallium(III) in aqueous hydrochloric acid solution

1975 ◽  
Vol 28 (9) ◽  
pp. 1901 ◽  
Author(s):  
SF Lincoln ◽  
AC Sandercock ◽  
DR Stranks
Keyword(s):  
Exchange Rate ◽  
Magnetic Resonance ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Hydrochloric Acid Solution ◽  
Magnetic Resonance Study ◽  
Aqueous Hydrochloric Acid ◽  
Chloride Exchange ◽  
Lower Limits ◽  
Aqueous Hydrochloric Acid Solution

The parameters describing chloride exchange on indium(III), determined by 35Cl N.M.R., are: k(298 K)= (8.8�0+4) x 106 s-1, ΔH? = 45.7�2.3 kJ mol-1 and ΔS? = 42�8 J mol-1 K-1; and k(298 K)= (2.0�0.1)x106 s-1, ΔH? = 37.7�1.9 kJ mol-1, and ΔS? = 3�6 J mol-1 K-1 in 10.95M and 7.00M aqueous hydrochloric acid respectively, calculated from the observed exchange rate kex4[InCl4(H2O)2-].��� For thallium(III) lower limits of kex(219 K) = 1.6 x 106 s-1 and 1.3 x 106 s-1 were obtained in 10.95M and 7.00M aqueous hydrochloric acid, respectively, where [TlCl6]3- is assumed to be the exchanging species.

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