Reactions of Phosphorus Pentachloride with Ethyl-, Vinyl-, and Ethynyl(trichloromethyl)carbinol and with 1,1,1-Trichloro-3-nonyn-2-ol

1973 ◽  
Vol 51 (12) ◽  
pp. 2017-2023 ◽  
Author(s):  
E. Wilkins Reeve ◽  
Thomas F. Steckel
Keyword(s):  
Vapor Phase ◽  
Acid Chloride ◽  
Phosphorus Pentachloride ◽  
Hydroxyl Group ◽  
Phosphate Ester ◽  
Allylic Rearrangement ◽  
Ethyl Vinyl ◽  
Normal Product

Reactions of phosphorus pentachloride with ethyl(trichloromethyl)carbinol (2), (trichloromethyl)-vinylcarbinol (7), ethynyl(trichloromethyl)carbinol (11a), and 1,1,1-trichloro-3-nonyn-2-ol (11b) have been studied. Whereas the reaction of phenyl(trichloromethyl)carbinol with phosphorus pentachloride leads to a nearly quantitative replacement of the hydroxyl group by chlorine, the reactions of the aliphatic (trichloromethyl)carbinols are more complicated. Thus the reaction of 2 with phosphorus pentachloride gave 18% of the normal product, 1,1,1,2-tetrachlorobutane (3), 13% of 1,1,2-trichloro-1-butene (4) from a dehydrohalogenation, and a higher boiling phosphate ester – acid chloride mixture. The alkynylcarbinols (11) gave tetrachlorobutynes (12) as well as tetrachloroallenes (13) by allylic rearrangement. A crystalline phosphate ester of 11a was also isolated. Several examples are given of catalytic rearrangements in the vapor phase of 1,1,1-trichloro-2-alkenes to 1,1,3-trichloro-1-alkenes.

scholarly journals Hydrogen Speciation in Hydrated Layers on Nuclear Waste Glass

1986 ◽  
Vol 84 ◽  
Author(s):  
Roger D. Aines ◽  
Homer C. Weed ◽  
John K. Bates
Keyword(s):  
Nuclear Waste ◽  
Vapor Phase ◽  
Waste Glass ◽  
Hydroxyl Group ◽  
Molecular Water ◽  
Hydroxyl Groups ◽  
Phase Layer ◽  
Nuclear Waste Storage ◽  
Nuclear Waste Glass ◽  
Saturated Atmosphere

AbstractThe hydration of an outer layer on nuclear waste glasses is known to occur during leaching, but the actual speciation of hydrogen (as water or hydroxyl groups) in these layers has not been determined. As part of the Nevada Nuclear Waste Storage Investigations Project, we have used infrared spectroscopy to determine hydrogen speciations in three nuclear waste glass compositions (SRL-131 & 165, and PNL 76-68), which were leached at 90°C (all glasses) or hydrated in a vapor-saturated atmosphere at 202°C (SRL-131 only). Hydroxyl groups were found in the surface layers of all the glasses. In addition, molecular water was found in the surface of SRL-131 and PNL 76-68 glasses that had been leached for several months in deionized water, and in the vapor-hydrated sample. The water/hydroxyl ratio increases with increasing reaction time; molecular water makes up most of the hydrogen in the thick reaction layers on vapor-phase hydrated glass while only hydroxyl occurs in the least reacted samples. Using the known molar absorptivities of water and hydroxyl in silica-rich glass the vapor-phase layer contained 4.8 moles/liter of molecular water, and 0.6 moles water in the form hydroxyl. A 15 micrometer layer on SRL-131 glass formed by leaching at 90°C contained a total of 4.9 moles/liter of water, 2/3 of which was as hydroxyl. The unreacted bulk glass contains about 0.018 moles/liter water, all as hydroxyl.The amount of hydrogen added to the SRL-131 glass was about 70% of the original Na + Li content, not the 300% that would result from alkali-hydronium ion (H30+) interdiffusion. If all the hydrogen is then assumed to be added as the result of alkali-H+ interdiffusion, the molecular water observed may have formed from condensation of the original hydroxyl groups according to:20H = H20 molecular + 00where 00 refers to a bridging oxygen, and OH refers to a hydroxyl group attached to a silicate polymer. The hydrated layer on the nuclear waste glasses appears to be of relatively low water content (4 to 7% by weight) and is not substantially hydroxylated. Thus, these layers do not have many of the properties associated with “gel” layers.

scholarly journals Synthesis and Characterizations of Dipeptide Derivative of Gentamicin

2019 ◽  
Vol 28 (2) ◽  
pp. 73-82
Author(s):  
Oun D. Khudair ◽  
Diar A. Fatih
Keyword(s):  
Acid Chloride ◽  
Solution Method ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Ester Linkage ◽  
Amine Groups ◽  
Conventional Solution ◽  
Dipeptide Derivative

Abstract       The target derivative are gentamicin linked with L-Val- L-Ala by an ester linkage. These were synthesized by esterification method, which included the reaction of -OH hydroxyl group on (carbon No.5) of gentamicin with the acid chloride of the corresponding dipeptide, The preparation of new derivative of gentamicin involved protected the primary & secondary amine groups of Gentamicin, by Ethylchloroformate (ECF) to give N-carbomethoxy Gentamicin which was used for further chemical synthesis involving the free hydroxyl groups. Then prepared dipeptide (L-Val- L-Ala) by conventional solution method in present DCC & HoBt then reacted with thionyl chloride to prepared acid chloride of dipeptides, then after, linked by ester linkage to N-protection gentamicin in present pyridine as base, finally deportation the amino group of synthesized compound by using TFAA in present anisole. The characterization of the titled compounds were performed utilizing FTIR spectroscopy, CHNS elemental analysis, and by measurements of their physical properties.  

Vapor-Phase Lubrication:  Reaction of Phosphate Ester Vapors with Iron and Steel

2002 ◽  
Vol 14 (9) ◽  
pp. 3767-3775 ◽  
Author(s):  
David W. Johnson ◽  
Samantha Morrow ◽  
Nelson H. Forster ◽  
Costandy S. Saba
Keyword(s):  
Vapor Phase ◽  
Phosphate Ester ◽  
Vapor Phase Lubrication ◽  
Iron And Steel

Investigation of Vapor-Phase Lubrication in a Gas Turbine Engine

1997 ◽  
Author(s):  
Kenneth W. Van Treuren ◽  
D. Neal Barlow ◽  
William H. Heiser ◽  
Matthew J. Wagner ◽  
Nelson H. Forster
Keyword(s):  
Gas Turbine ◽  
Vapor Phase ◽  
Gas Turbine Engine ◽  
Rolling Contact ◽  
Phosphate Ester ◽  
Lubrication System ◽  
Oil Lubrication ◽  
Vapor Phase Lubrication ◽  
Engine Operation ◽  
Turbine Engine

The liquid oil lubrication system of current aircraft jet engines accounts for approximately 10–15% of the total weight of the engine. It has long been a goal of the aircraft gas turbine industry to reduce this weight. Vapor-Phase Lubrication (VPL) is a promising technology to eliminate liquid oil lubrication. The current investigation resulted in the first gas turbine to operate in the absence of conventional liquid lubrication. A phosphate ester, commercially known as DURAD 620B, was chosen for the test. Extensive research at Wright Laboratory demonstrated that this lubricant could reliably lubricate railing element bearings in the gas turbine engine environment. The Allison T63 engine was selected as the test vehicle because of its small size and bearing configuration. Specifically, VPL was evaluated in the number eight bearing because it is located in a relatively hot environment, in line with the combustor discharge, and it can be isolated from the other bearings and the liquid lubrication system. The bearing was fully instrumented and its performance with standard oil lubrication was documented. Results of this baseline study were used to develop a thermodynamic model to predict the bearing temperature with VPL. The engine was then operated at a ground idle condition with VPL with the lubricant misted into the #8 bearing at 13 ml/hr. The bearing temperature stabilized at 283°C within 10 minutes. Engine operation was continued successfully for a total of one hour. No abnormal wear of the rolling contact surfaces was found when the bearing was later examined. Bearing temperatures after engine shutdown indicated the bearing had reached thermodynamic equilibrium with its surroundings during the test. After shutdown bearing temperatures steadily decreased without the soakback effect seen after shutdown in standard lubricated bearings. In contrast, the oil lubricated bearing ran at a considerably lower operating temperature (83°C) and was significantly heated by its surroundings after engine shutdown. In the baseline tests, the final bearing temperatures never reached that of the operating VPL system.

A proton magnetic resonance estimate of the extent of intramolucular hydrogen bonding in derivatives of 2-trifluoromethyl phenol. Solvent effects

1976 ◽  
Vol 54 (14) ◽  
pp. 2243-2248 ◽  
Author(s):  
Ted Schaefer ◽  
J. Brian Rowbotham
Keyword(s):  
Free Energy ◽  
Hydrogen Bonding ◽  
Vapor Phase ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Hydroxyl Group ◽  
Spin Coupling Constants ◽  
Hydroxyl Protons ◽  
Spin Spin Coupling ◽  
Derivatives Of

The long-range spin–spin coupling constants between hydroxyl protons and ring protons or fluorine nuclei are used to establish the conformer populations in iodine and brornine derivatives of 2-trifluoromethylphenol in C6H12, CCl4, and C6D6 solutions. The sequence Cl, [Formula: see text] is established for the so-called hydrogen bonding preferences of the hydroxyl group in 2,4,6-trisubstituted phenols, the corresponding free energy sequence being −ΔG = 1690, 1690 > 1300 > 1230 > 0 ± 200 cal/mol at 32 °C in CCl4 solution. An indirect estimate of the free energy differences in the vapor phase suggests the sequence −ΔG = 2800, 2800 > 2400 > 2300 > 1100 ± 300 cal/mol; the latter value meaning that the hydroxyl group in 4-bromo-2-trifluoromethylphenol prefers the CF3 group by this amount in the vapor phase. Benzene interacts preferentially with the OH group in this compound to the extent of 1300 cal/mol (ΔG), referenced to the vapor phase.

Synthesis and evaluation of novel mutual prodrugs of Piroxicam

2017 ◽  
Vol 4 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Vivekkumar K Redasani ◽  
Omkar C. Bhalerao ◽  
Mohan G. Kalaskar ◽  
Sanjay J. Surana
Keyword(s):  
Side Effects ◽  
Synergistic Effect ◽  
Acid Chloride ◽  
Mefenamic Acid ◽  
Phosphate Buffer ◽  
Therapeutic Efficacy ◽  
Hydroxyl Group ◽  
Alkaline Ph ◽  
Gastrointestinal Side Effects ◽  
Mutual Prodrug

Therapeutic efficacy of piroxicam can be improved by retarding gastrointestinal side effects by means of temporarily modification of enolic hydroxyl group chemically. The NSAIDs such as aceclofenac, ibuprofen, mefenamic acid and naproxen were selected as promoities with the aim of getting synergistic effect through these well known pharmaco-counter parts. The targeted prodrugs are synthesized successfully and confirmed by characterization. Synthesis involved chlorination of NSAIDs and coupling of this acid chloride with piroxicam through enolic hydroxyl group to get ester derivatives. Mutual prodrugs were evaluated by hydrolysis study at different pH (acidic, neutral, alkaline) using phosphate buffer. Prodrug derivatives were found to be stable at acidic and neutral pH but prone to hydrolysis at alkaline pH. Thus the objective of the presented study was to overcome the undesirable side effects of NSAIDs. Thus, current studies confirms that the mutual prodrug approach can be applied  effectively in order to  achieve the purpose of raising effectiveness of piroxicam under two lines; firstly, masking of enolic hydroxyl group through acids and converting them to esters and secondly, utilizing the known NSAIDs for achieving the synergistic effect.

THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND OF ORTHO-ALKYL PHENOLS IN THE VAPOR PHASE

1962 ◽  
Vol 40 (1) ◽  
pp. 111-121 ◽  
Author(s):  
K. U. Ingold
Keyword(s):  
Vapor Phase ◽  
Hydroxyl Group ◽  
Trans Isomers ◽  
Polar Solvents ◽  
Cis And Trans Isomers ◽  
Stretching Vibration ◽  
Alkyl Phenols ◽  
Infrared Frequencies ◽  
Cis And Trans ◽  
Hydroxyl Band

The infrared frequencies and intensities of the fundamental stretching vibration of the hydroxyl group have been measured for a number of ortho-alkyl phenols in the vapor phase over a range of temperatures. Both quantities have been shown to depend on internal steric and environmental factors. The differences in enthalpy between the cis and trans isomers of several 2-tert-alkyl phenols have been measured, and it is concluded that the latter are not significantly stabilized relative to the former by solvation in non-polar solvents.

The Allylic Rearrangement of the Hydroxyl Group from C-9 to C-13 and the Absolute Configuration at C-9 of Leucomycin A3

1968 ◽  
Vol 16 (7) ◽  
pp. 1402-1404 ◽  
Author(s):  
SATOSHI OMURA ◽  
MICHIKO KATAGIRI ◽  
TOJU HATA ◽  
MIKIO HIRAMATSU ◽  
TERUTOSHI KIMURA ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Hydroxyl Group ◽  
Allylic Rearrangement ◽  
The Absolute

Investigation of Vapor-Phase Lubrication in a Gas Turbine Engine

1998 ◽  
Vol 120 (2) ◽  
pp. 257-262 ◽  
Author(s):  
K. W. Van Treuren ◽  
D. N. Barlow ◽  
W. H. Heiser ◽  
M. J. Wagner ◽  
N. H. Forster
Keyword(s):  
Gas Turbine ◽  
Vapor Phase ◽  
Gas Turbine Engine ◽  
Rolling Contact ◽  
Phosphate Ester ◽  
Lubrication System ◽  
Oil Lubrication ◽  
Vapor Phase Lubrication ◽  
Engine Operation ◽  
Turbine Engine

The liquid oil lubrication system of current aircraft jet engines accounts for approximately 10–15 percent of the total weight of the engine. It has long been a goal of the aircraft gas turbine industry to reduce this weight. Vapor-Phase Lubrication (VPL) is a promising technology to eliminate liquid oil lubrication. The current investigation resulted in the first gas turbine to operate in the absence of conventional liquid lubrication. A phosphate ester, commercially known as DURAD 620B, was chosen for the test. Extensive research at Wright Laboratory demonstrated that this lubricant could reliably lubricate rolling element bearings in the gas turbine engine environment. The Allison T63 engine was selected as the test vehicle because of its small size and bearing configuration. Specifically, VPL was evaluated in the number eight bearing because it is located in a relatively hot environment, in line with the combustor discharge, and it can be isolated from the other bearings and the liquid lubrication system. The bearing was fully instrumented and its performance with standard oil lubrication was documented. Results of this baseline study were used to develop a thermodynamic model to predict the bearing temperature with VPL. The engine was then operated at a ground idle condition with VPL with the lubricant misted into the #8 bearing at 13 ml/h. The bearing temperature stabilized at 283°C within 10 minutes. Engine operation was continued successfully for a total of one hour. No abnormal wear of the rolling contact surfaces was found when the bearing was later examined. Bearing temperatures after engine shutdown indicated the bearing had reached thermodynamic equilibrium with its surroundings during the test. After shutdown bearing temperatures steadily decreased without the soakback effect seen after shutdown in standard lubricated bearings. In contrast, the oil-lubricated bearing ran at a considerably lower operating temperature (83°C) and was significantly heated by its surroundings after engine shutdown. In the baseline tests, the final bearing temperatures never reached that of the operating VPL system.

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