Ethanol 8-elimination

Alcohols undergo dehydration in supercritical and hot water (41). Tertiary alcohols require no catalyst, but secondary and primary alcohols require an acid catalyst. With 0.01 MH2SO4 as a catalyst, ethanol eliminates water at 385°C and 34.5 MPa to form ethene. Reaction occurs in tens of seconds. Only a small amount of diethyl ether forms as a side reaction. 

Elevated acetaldehyde levels are associated with a decrease in ethanol elimination rate, consistent with the product inhibition of ADH activity. 

Reiter and co-workers found in the course of their extended research on fused [l,2,4]triazines <1994JHC997> that the N-protected methylthiotriazine derivative 110 when reacted with carbon disulfide under strongly basic conditions yields a mixture of two products 111 and 112. When this mixture was treated with dibromomethane, product 113 was easily removed from the reaction mixture, and workup of the mother liquor allowed the isolation of the [l,2,4]triazolo[l,5-c][l,3,5]thiadiazine derivative 114 in 49% yield (Scheme 21). The same authors carried out ring closure of the ring-closed semithiocarbazide 115 to the triazolothiadiazine derivative 118 as shown in Scheme 21 <1997JHC1575>. The starting compound was treated with triethyl orthoformiate. The authors assume that first intermediate 116 is formed which cyclizes to a second intermediate 117 and, finally, ethanol elimination yields the isolated product 118. 

Use has been made of the bond cleavage processes initiated by an adjacent carbonyl function for the modification of steroidial ketols such as 18 [97], Reduction in ethanol eliminates the hydroxyl function and in the same reaction, the carbonyl function is reduced to a secondary alcohol. In compound 19 where there are several groups to act as electrophores, carbon-oxygen bond cleavage is initiated from the most easily reduced dienone function [98], Cleavage of the carbon-oxygen bond in an a-acetoxycarbonyl function is achievable in good yields from multifunctional compounds such as the sesquiterpene taxol [99]. 

The acetoxy group of 9-(l-acetoxyethyl)carbazole is easily displaced with alcohols. Easy displacement of a similarly situated halogen can be achieved, as has been noted before (see Section II,C,2) thus methanol converts 9-(l-chloro-2-iodoethyl)carbazole to 9-(2-iodo-l-methoxyethyI) car-bazole. Elimination of acetic acid or ethanol by strongly heating 9-(l-acetoxyalkyl)- or 9-(l-ethoxyalkyl)carbazoles gives 9-vinylcarbazoles. In the absence of acid, ( )-alkenes are produced, but acid catalysis leads to a mixture of E and Z isomers. Acetyl chloride in pyridine also effects ethanol elimination. ... 

Another work of Duhamel and Ancel [59] related this synthesis of retinal via (3-ionylideneacetaldehyde. Condensation of methallyl-magnesium chloride with diethyl phenyl orthoformate (EtC CHOPh) led after bromination of the ene-acetal, deshydrohalogenation (NaOH 50%), ethanol elimination with hexamethyldisilazane (HMDS) and ISiMes, to the bromo-dienol ether. This latter was submitted to bromine lithium exchange and the lithio enol ether was then condensed with p ionylideneacetaldehyde to give retinal, Fig. (28). 

A convenient synthesis of thieno[2,3-6]quinoline (Scheme 111) (76ZN(B)1297,76ZN(B)1685, 77JCS(P1)2024) utilizes the readily available methyl 2-oxo-3-vinyl-l//-quinoIin-4-carboxylate (380) as starting material. Treatment of (380) with phosphorus oxychloride yields the chloroquinoline which on addition of bromine gives a trihalo compound. The cyclization to (381) is effected with thiourea in boiling ethanol. Elimination of the methoxycarbonyl group yields thieno[2,3-6]quinoline as colorless needles with m.p. 107-108 °C, which can be characterized as the picrate with m.p. 213-214 °C. 

The uncatalyzed H02 elimination from the peroxyl radical derived from methanol is too slow to be measured at room temperature (k < 10 s-1). That derived from ethanol eliminates H02" with k = 52 s and that derived from isopropyl alcohol undergoes an even faster elimination of HOj (k = 665 s-1). The activation energies are,T —60 kj. mol-1. If OH - acts as the base, reaction 38 occurs at rates that are near to diffusion-controlled. The catalysis by phosphate is three orders of magnitude slower. 

Bauer LA, Schumock G, Horn J, Opheim K. Verapamil inhibits ethanol elimination and prolongs the perception of intoxication. Clin Pharmacol Ther 1992 52 6-10. Bjornsson TD, Callaghan JT, Einolf HJ et al. The conduct of in vitro and in vivo drug-drug interaction studies a PhRMA perspective./Clin Pharmacol 2003 43 443-69. Dasgupta A, Bernard DW. Herbal remedies effects on clinical laboratory tests. Arch Pathol Lab Med 2006 130 521-8. 

Side group reactions are common during pyrolysis and they may take place before chain scission. The presence of water and carbon dioxide as main pyrolysis products in numerous pyrolytic processes can be explained by this type of reaction. The reaction can have either an elimination mechanism or, as indicated in Section 2.5 for the decarboxylation of aromatic acids, it can have a substitution mechanism. Two other examples of side group reactions were given previously in Section 2.2, namely the water elimination during the pyrolysis of cellulose and ethanol elimination during the pyrolysis of ethyl cellulose. The elimination of water from the side chain of a peptide (as shown in Section 2.5) also falls in this type of reaction. Side eliminations are common for many linear polymers. However, because these reactions generate smaller molecules but do not affect the chain of the polymeric materials, they are usually continued with chain scission reactions. 

Charged and uncharged species tend to interact with the solvent differently, i.e. there is differential solvation. This can also be achieved by changing the solvent in which the reaction is performed, e g. by changing the solvent from water to ethanol elimination is thereby favoured over substitution. 

Ainsworth S obtained a much better yield in the formylation of cyclohexanone in a process in which sodium ethoxide was generated in situ from 1 equivalent of sodium and the ethanol eliminated in the condensation. A mixture of cyclohexanone. 

Bogusz M, Poch J, Stasko W. Comparative studies on the rate of ethanol elimination in acute poisoning and in controlled conditions. J Forensic Sci 1977 22 446-51. 

ADH 2 and ADH 3 are present as functional polymorphisms that differ in their properties. Genetic polymorphisms for ADH partially account for the observed differences in ethanol elimination rates among various individuals or populations. Although susceptibility to alcoholism is a complex function of genetics and socioeconomic factors, possession of the ADH 2 2 allele, which encodes a relatively fast ADH (high is associated with a... 

Finally, insertion of alkynes into dihydrogen mononuclear cationic rhenium complexes, stabilized by the triphos (= l,l,l-tris(diphenylphosphinomethyl)ethane) ligand, leads to vinylidene derivatives which react with water or ethanol eliminating silanols or methane, Fig. 18. Solvents were acetone or THF no chromatography was used. 

Condensation of diethyl butyl malonate and />-benzyloxyhydrazo-benzene is done in the presence of sodium ethoxide in anhydrous ethanol to yield l-(benzyloxy)-2-phenyl-4-butyl-3, 5-pyrazolidinedione. The reaction mixture is heated with xylene to about 140°C for several hours which aids in the removal ethanol eliminated by cyclization. The resulting product is debenzylated by the aid of Raney Nickel hydrogenation at an ambient temperature and pressure. The crude product may be recrystallized from ether/petroleum ether. 

Doses may vary depending on the Individual. Chronic alcoholics have a higher rate of ethanol elimination, and maintenance doses should be adjusted to maintain an ethanol level of approximately 100 mg/dL. 

B. Increase the infusion rate to 175-250 mg/kg/h (larger dose for chronic alcoholics) during hemodialysis to offset the increased rate of ethanol elimination. Alternately, ethanol may be added to the dialysate. 

I.R. spectrum of heat-treated 4,4 -dibenzamido-6-ethoxycarbnyl benzanilide(Fig. 3) showed a strong lacton carbonyl absorption band at 1,746 cm and ether absorption band at 1,053 cm, suggesting the formation of benzoxazinone derivative by the ethanol elimination reaction between ethoxycarbonyl group and amide bond. 

On the other hand, if the solvent is protic (such as methanol or ethanol), elimination is known to be faster than substitution because solvation of the nucleophile/base will slow down the 8 2 rate of reaction. Therefore, assume that protic solvents favor elimination. If the solvent for the reaction of sodium methoxide and a secondary halide is changed to methanol (a protic solvent), an E2 reaction will predominate to give the alkene. 

Because of the uses of ethanol in the newborn and in pregnant patients, where it readily transverses the placental barrier and becomes distributed evenly in the maternal and fetal blood stream (Belinkoff and Hall, 1950), it seems important that the capabilities of ethanol elimination by both fetus and newborn be known. 

Fragmentation of vinylic and acetylenic alkyl ethers Dominant homolysis of the alkyl C-C bond next to the O atom on the saturated side, leading to C3H50 (m/z 57) for vinylic and C3H30 (m/z 55) for acetylenic ethers of primary aliphatic alcohols. For alkyl (C 5) vinyl ethers, ethanol elimination after triple H transfer. [M-15]+ in vinyl ethers predominantly by elimination of the vinyl CH2 after H rearrangement. 

On the contrary, when 87a was reacted with ethyl propynoate, isocoumarins 262 were obtained. In this case the Diels-Alder cycloadduct 261 reacted as diene with another ethyl propynoate molecule. Tricyclic pyran underwent oxygen bridge opening followed by ethanol elimination presumably catalyzed by acidic Pyrex reaction tube walls [75, 78, 151]. Reaction of 110 with ethyl propynoate yielded complex mixture of unidentified products [78]. 

Also obtained by reaction of ethyl nitrite with 2-amino-5-chloro -hydroxybenzophenone in refluxing ethanol (elimination of amino group) [925]. 

Heating the films may be a simple way to remove the salt. Additional XRD studies showed that washing an AAB gel with ethanol eliminates the salt, so washing the films might also work. It would be better, however, if we found the irfini-mum catalyst level that eliminates the small pore-plugging species. A new sol with less catalyst might also have D values that fall between those of B2 and AAB, and an intermediate value of D should produce more porous as-deposited films. 

Elimination (or Dehydration) In the presence of concentrated acids such as H2SO4, alcohols react and eliminate water, forming an alkene. For example, ethanol eliminates water to form ethene according to the reaction ... 

In connection with studies on the thermolysis of oxazolin-5-ones, the 2-arylthio-substituted derivative (49) has been observed to undergo thermally induced cycloelimination of carbon dioxide to give the 2H-1,3-benzothiazine (52), presumably via the ylide intermediates (50) and (51). Like 2-ethoxybenzoxazin-4-one, the sulphur analogue (53) undergoes ethanol elimination under the influence of an acid catalyst to give the unstable cyclic acylamine (54), which can be trapped as Diels-Alder adducts... 

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