Cleavage of 3,3,4-trifluoro-2,2-dimethyloxetane by mineral acids

1985 ◽  
Vol 50 (9) ◽  
pp. 1948-1958 ◽  
Author(s):  
Václav Dědek ◽  
Ivan Veselý
Keyword(s):  
Aqueous Solution ◽  
Phosphoric Acid ◽  
Sulphuric Acid ◽  
Hydrobromic Acid ◽  
Polyphosphoric Acid ◽  
Acetyl Chloride ◽  
Main Product ◽  
Hydrogen Bromide ◽  
Mineral Acids ◽  
Sole Product

Cleavage of 3,3,4-trifluoro-2,2-dimethyloxetane (I) in an aqueous solution of sulphuric acid, phosphoric acid, hydrogen chloride, or hydrogen bromide gave a mixture of 2,2-difluoro-3-methyl-3-butenal (II) and 5,5-difluoro-2-(1,1-difluoro-2-hydroxy-2-methylpropyl)-4-hydroxy-6,6-dimethyl-1,3-dioxane (VIa); in the cleavage effected by hydrochloric or hydrobromic acid the mixture also contained 3-chloro- or 3-bromo-2,2-difluoro-3-methyl-1,1-butanediol (Vb or Vc). In alcoholic solutions of the mineral acids the cleavage afforded the corresponding acetals of butenal II and 2,2-difluoro-3-hydroxy-3-methylbutanal (IIIa). The action of sulphuric acid in the presence of acetyl chloride or acetanhydride led to 1-chloro-2,2-difluoro-3-methyl-3-butenyl acetate (IVd) or 2,2-difluoro-3-methyl-3-butenylidene diacetate (IVe), as the main product. Butenal II was a sole product of the cleavage of oxetane I by polyphosphoric acid at 150-160 °C in the gaseous phase. At temperatures above 180 °C there were also formed (in addition to butenal II) 1,1,5,5-tetrafluoro-2,6-dimethyl-1,6-heptadiene-4-ol (IX) and its formate (X).

scholarly journals Studies on Chitin V. The Action of Mineral Acids on Chitin

1962 ◽  
Vol 15 (3) ◽  
pp. 526 ◽  
Author(s):  
RH Hackman
Keyword(s):  
Hydrochloric Acid ◽  
Phosphoric Acid ◽  
Sulphuric Acid ◽  
Chain Length ◽  
Colloidal Chitin ◽  
Mineral Acids ◽  
Extensive Degradation

Chitin undergoes rapid and extensive degradation at 20�C when dissolved in ION hydrochloric acid, 21N sulphuric acid, or 85% phosphoric acid. Most of the degradation occurs in the first few minutes after the chitin is dissolved and the products formed are oligosaccharides (which are to some extent deacetylated) and N�acetyl-D.glucosamine. Glucosamine was not found except possibly in the smallest traces. "Colloidal" chitin, prepared by precipitation of chitin from solution in cold 21N sulphuric acid, has a very much shorter chain length than the chitin from which it was prepared. Chitin is more stable in dilute (2N) hydrochloric acid.

Synthesis of new dibenzo[b,e]thiepin derivatives related to the antidepressant agent prothiadene

1979 ◽  
Vol 44 (8) ◽  
pp. 2536-2549 ◽  
Author(s):  
Miroslav Rajšner ◽  
Václav Bártl ◽  
Karel Šindelář ◽  
Emil Svátek ◽  
Jiří Holubek ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Primary Amine ◽  
Hydrobromic Acid ◽  
Main Product ◽  
Hydrogen Bromide ◽  
Geometric Isomers ◽  
Bromo Derivative ◽  
Antidepressant Agent ◽  
Boron Tribromide

A reaction of dibenzo[b,e]thiepin-11(6H)-one with cyclopropylmagnesium bromide afforded the carbinol VII giving by treatment with hydrogen bromide the bromo derivative IV. Application of the Gabriel synthesis led to the primary amine III postulated earlier to be a metabolite of the antidepressant agent prothiadene (I). Demethylation of 2-methoxy-11-(3-dimethylaminopropylidene)-6,11-dihydrodibenzo[b,e]thiepin (X) with boron tribromide or hydrobromic acid gave mixtures of geometric isomers of the phenol IX from which either the trans- or cis-form could be isolated; trans-IX is another potential metabolite of prothiadene (I). Attempts at preparing prothiadene N-oxide yielded as the main product the nitrogen-free diene XI which was apparently formed by a Cope elimination. The analogous sulfone XII was obtained as a by-product of the preparation of prothiadene S,S-dioxide (XV). Treatment of dibenzo[b,e]thiepin-11(6H)-one with methoxymethylmagnesium chloride opened the access to the aldehyde XVI which was further used for the preparation of the nitrile XVIII, alcohol XIX, carboxylic acid XX and acrylic acid XXI.

The synthesis of Cyclododecane-r-1,c-5,c-9-triamine and r-1,c-5,c-9-Tris(2,3-dimethoxybenzamido)cyclododecane

1975 ◽  
Vol 28 (3) ◽  
pp. 673 ◽  
Author(s):  
DJ Collins ◽  
C Lewis ◽  
JM Swan
Keyword(s):  
Aqueous Solution ◽  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Sodium Carbonate ◽  
Sodium Azide ◽  
Room Temperature ◽  
Dimethyl Formamide ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Hydrolysis Of

Treatment of cyclododecane-r-1,c-5,c-9-triyl tris(p-toluenesulphonate) with sodium azide in dimethyl-formamide at 100� for 6 h gave the corresponding cis,cis-triazide which upon hydrogenation or reduction with lithium aluminium hydride gave cyclododecane-r-1,c-5,c-9-triamine, isolated as the tris-salicylidene derivative. Acid hydrolysis of this, removal of the salicylaldehyde, and treatment of the aqueous solution with sodium carbonate and 2,3-dimethoxybenzoyl chloride gave r-1,c-5,c- 9-tris(2,3-dimethoxybenzamido)cyclododecane. ��� Treatment of (E,E,E)-cyclododeca-1,5,9-triene with an excess of acetonitrile and sulphuric acid at room temperature for three days gave 18% of (E,E)-1-acetamidocyclododeca-4,8-diene; no di- or tri-amides were isolated.

scholarly journals Synthesis of 3-Ferrocenyl Isocoumarins

2020 ◽  
Vol 36 (05) ◽  
pp. 976-979
Author(s):  
Neeta Sinha
Keyword(s):  
Spectral Analysis ◽  
Melting Point ◽  
Phosphoric Acid ◽  
Polyphosphoric Acid ◽  
Aluminium Chloride ◽  
Melting Point Determination ◽  
Anhydrous Aluminium Chloride ◽  
Point Determination ◽  
Derivatives Of

The derivatives of 3-ferrocenyl isocoumarin were synthesized by the condensation of substituted homothphalic anhydride with ferrocene using phosphoric acid or anhydrous aluminium chloride as cyclising agent. Substituted homophthalic acid did not condense with ferrocene so homophthalic acids were converted into their anhydride and then allowed to react with ferrocene in the presence of polyphosphoric acid or in the presence of anhydrous aluminium chloride using dichloromethane as the solvent to give 3-ferrocenyl isocoumarins. 7-Methoxy, 6-methyl, 5,7-dihydroxy, 6,7-dimethoxy and 5,7-dimethoxy derivatives of 3-ferrocenyl isocoumarin were synthesized. All the compounds were characterised by melting point determination, elemental and spectral analysis.

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