Reaction of trans-2-Acylaminocyclanols with Thionyl Chloride

1971 ◽  
Vol 49 (12) ◽  
pp. 2064-2072 ◽  
Author(s):  
R. A. B. Bannard ◽  
N. C. C. Gibson ◽  
J. H. Parkkari
Keyword(s):  
Thionyl Chloride ◽  
Half Life ◽  
Spectral Characteristics ◽  
High Yield ◽  
Methyl Proton ◽  
Reaction Solution ◽  
Crude Product ◽  
Proton Resonances ◽  
General Method

trans-2-Acetamidocyclohexanol (1; n = 2, R = CH3) on addition to thionyl chloride in chloroform at 0° was converted rapidly and quantitatively to D,L-2-methyl-4,5-cis-cyclohexanoöxazoline hydrochloride (2; n = 2, R = CH3) judging from shifts in the methyl proton resonances of the n.m.r. spectra of the amide and the reaction solution. The intermediate chlorosulfinate was estimated to have a half-life of less than 2.25 min. The oxazoline salt was isolated in 98% yield by sublimation of the crude product in vacuo and was identified by its i.r. and n.m.r. spectra and by its facile and almost quantitative hydrolysis to cis-2-aminocyclohexanol hydrochloride. The oxazoline salts 2 (n = 1, R = CH3, [Formula: see text] and n = 2, R = C6H5, [Formula: see text]) were readily obtained in 95 % yield or better by the same general method and it was shown that the trans-2-acetamidocyclanols are the preferred starting materials for conversion to cis-2-aminocyclanol derivatives by the thionyl chloride inversion reaction. The oxazoline bases 4 (n = 1, R = CH3, [Formula: see text] and n = 2, R = CH3, [Formula: see text]) were readily obtained in high yield from the corresponding salts and differences in the i.r. and n.m.r. spectral characteristics of the salts and bases are reported.

Gold Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Reaction Pathways to Access 1,3-Aminoalcohols, 3-Hydroxyketones or 3-Aminoketones

2018 ◽  
Author(s):  
Victor Laserna ◽  
Tom Sheppard
Keyword(s):  
Gold Catalysis ◽  
Reaction Pathways ◽  
High Yield ◽  
Reaction Conditions ◽  
Propargylic Alcohols ◽  
Catalytic Quantity ◽  
Selective Formation ◽  
General Method

A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. Firstly, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxy imines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-aminoalcohols with high syn seletivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway.<br>

2-Hydroxyimino-1,3-indandione Salts with Ammonia and Amines

1990 ◽  
Vol 45 (4) ◽  
pp. 543-546 ◽  
Author(s):  
St. Minchev ◽  
V. Enchev ◽  
H. Nedev
Keyword(s):  
Spectral Characteristics ◽  
High Yield ◽  
Nitroso Group ◽  
Mndo Calculations

The preparation, structure and spectral characteristics of intensely colored salts of 2-hydroxyimino-1,3-indandione with ammonia and amines are described. The crystallization of the salts takes place with a high yield. All the salts fluoresce in DMSO. MNDO calculations show that the formation of an anion from 2-hydroxyimino-1,3-indandione is associated with substantial alterations in the nitroso group.

Heparin Small Pool High Yield Purified Factor VIII: In Vivo Recovery and Half-Life of Routinely Produced Freeze-Dried Concentrate

1984 ◽  
Vol 51 (01) ◽  
pp. 012-015 ◽  
Author(s):  
C T Smit Sibinga ◽  
S M G J Daenen ◽  
G W van Imhoff ◽  
A Maas ◽  
P C Das
Keyword(s):  
Side Effects ◽  
Factor Viii ◽  
Half Life ◽  
High Yield ◽  
Freeze Dried ◽  
Acute Side Effects ◽  
Significant Difference ◽  
Small Pool ◽  
Process Work

SummaryNew approaches and techniques for improving source material collection and Factor VIII production at Blood Bank level have been reported recently.Heparin has been shown to be of importance in increasing yields and stability of FVIII in the purification and concentration process. Work has been done to develop on a routine scale the heparin double cold precipitation technique for the production of a freeze-dried high yield purified FVIII concentrate.The product has been tested clinically in 4 severe hemophilia A patients for recovery, half-life and acute side-effects, using two dosages over 8 infusions. There was no significant difference between the two dosages. Mean recovery 99.1% and mean halflife 8 hr, ranging from 6.5 to 10.3 hr.No side-effects were observed.These results justify further exploration of the potential of heparin for high yield purified FVIII production.

O-Isopropylidene derivatives of D-allulose (D-psicose) and D-erythro-hexopyranos-2,3-diulose

1968 ◽  
Vol 46 (8) ◽  
pp. 765-770 ◽  
Author(s):  
G. M. Cree ◽  
A. S. Perlin
Keyword(s):  
Deuterium Oxide ◽  
Spectral Characteristics ◽  
High Yield ◽  
Partial Acid Hydrolysis ◽  
Hydride Reduction ◽  
Sodium Amalgam ◽  
Isopropylidene Derivatives ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Sole Product

Oxidation of 1,2: 4,5-di-O-isopropylidene-β-D-fructopyranose (2) with ruthenium tetroxide affords crystalline 1,2: 4,5-di-O-isopropylidene-β-D-erythro-hexopyranos-2,3-diulose (3) in high yield. The latter, on reduction with metal hydrides or on catalytic hydrogenation over platinum, yields 1,2: 4,5-di-O-isopropylidene-β-D-allulopyranose (4) as virtually the sole product. By contrast, sodium amalgam reduction of 3 yields only the D-fructose derivative (2), although in low yield. Also, metal hydride reduction of impure 3, obtained by oxidation of 2 with dimethyl sulfoxide – acetic anhydride, yields equal amounts of both isomers (2 and 4). The stereochemistry of these reductions is complicated by uncertainty as to the conformation of 4 (and possibly of 2), owing to anomalous proton magnetic resonance spectral characteristics observed.Ketone 3, which is unstable in the presence of deuteroxide ion, is smoothly deuterated at C-4 by exchange in hot deuterium oxide – pyridine.Mono-O-isopropylidene derivatives have been prepared by partial acid hydrolysis of 2 and 4.

Chlorosulfination of Aromatic Methyl Ethers with Thionyl Chloride

1985 ◽  
Vol 38 (8) ◽  
pp. 1209 ◽  
Author(s):  
KH Bell
Keyword(s):  
Thionyl Chloride ◽  
Room Temperature ◽  
Starting Material ◽  
High Yield

Aromatic sulfinyl chlorides have been prepared in high yield by direct chlorosulfination of some aromatic ethers (1,3-dimethoxybenzene, 2- methyl- and 4-chloro-1,3-dimethoxybenzene, 1,2,3-trimethoxybenzene, 1- and 2-methoxynaphthalene, 1,5-, 1,7-, 2,6- and 2,7- dimethoxynaphthalene ) with thionyl chloride alone at or below room temperature. Under the same conditions, 1,4-dimethoxynaphthalene and 1,3-dimethoxy-5-methylbenzene yield chlorinated starting materials and sulfides. 1,3,5-Trimethoxybenzene yields chlorinated starting material, sulfide, and a chlorinated disulfide. Some other ethers (e.g. anisole, 1,2- and 1,4-dimethoxybenzene, 5-chloro-1,3-dimethoxybenzene) are unreactive under these conditions.

Time-resolved spectroscopic studies of the photochemistry of some diphenylgermylene (Ph2Ge:) precursors

2005 ◽  
Vol 83 (9) ◽  
pp. 1324-1338 ◽  
Author(s):  
Cameron R Harrington ◽  
William J Leigh ◽  
Bryan K Chan ◽  
Peter P Gaspar ◽  
Dong Zhou
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Spectral Characteristics ◽  
Complex Mixture ◽  
Laser Flash ◽  
Spectroscopic Studies ◽  
Major Product ◽  
High Yield ◽  
Time Resolved

The photochemistry of diphenylbis(trimethylsilyl)germane (2a) and 1,4-dihydro-5-methyl-1,2,3,4,9,9-hexaphenyl-1,4-germanonaphthalene (11) has been studied in solution by steady-state and laser flash photolysis methods with a view to detecting the transient germylene derivative diphenylgermylene (Ph2Ge), which has previously been shown to be the major product of photolysis of 2a and a closely related derivative of 11. Steady-state trapping experiments confirm the formation of Ph2Ge as the major germanium containing primary product in both cases; with 2a, the results indicate that other transient species are also formed in minor yields, including phenyl(trimethylsilyl)germylene (Ph(TMS)Ge, ca. 6%) and diphenyl(trimethylsilyl)germyl radicals (Ph2(TMS)Ge, ≥15%). Laser flash photolysis of 2a in deoxy genated hexane solution yields a complex mixture of overlapping transient absorptions, which is shown to be comprised of Ph2Ge, tetraphenyldigermene (15) and its oligomerization products, and another species with spectral characteristics similar to the Ph2(TMS)Ge radical. The latter has been independently generated by hydrogen abstraction from diphenyl(trimethylsilyl)germane by tert-butoxyl radicals. Compound 11 extrudes Ph2Ge more cleanly and efficiently upon photolysis in solution, yet laser flash photolysis affords excited triplet and triplet-derived species as the only detectable transient products; interpretation of the results for this compound is made difficult by its slow thermal decomposition to 5-methyl-1,2,3,4-tetraphenylnaphthalene. It is concluded that in spite of the fact that both 2a and 11 afford Ph2Ge in high yield upon photolysis, they are poor precursors for study of the species in solution by time-resolved UV–vis methods, owing to the formation of other, more strongly absorbing transient products than Ph2Ge, whose lowest energy absorption is characteristically weak.Key words: germylene, germyl radical, flash photolysis, disilylgermane, photochemistry.

scholarly journals THE RELATIVE ACCEPTOR POWER OF BORON TRIHALIDES AND BORANE TOWARD TRIMETHYLAMINE BY PROTON N.M.R. MEASUREMENTS

1964 ◽  
Vol 42 (7) ◽  
pp. 1518-1523 ◽  
Author(s):  
J. M. Miller ◽  
M. Onyszchuk
Keyword(s):  
Linear Relationship ◽  
Chemical Shifts ◽  
Dipole Moments ◽  
Chloroform Solution ◽  
Heats Of Formation ◽  
Methyl Proton ◽  
Acceptor Activity ◽  
Proton Resonances ◽  
Proton Chemical Shifts

Proton n.m.r. spectra of trimethylamine adducts of the boron trihalides and borane have been measured in chloroform solution. Chemical shifts of methyl protons relative to tetramethylsilane decrease in the order: BBr3 > BCl3 > BH3 > BF3, suggesting that this is the order of acceptor activity toward trimethylamine. This is supported by the existence of a linear relationship between methyl proton chemical shifts and the heats of formation, dipole moments, or infrared vibrational shifts of boron trihalide and borane adducts. Splitting of methyl proton resonances into quartets have been observed for (CH3)3N•BCl3 and (CH3)3N•BBr3 but not for (CH3)3N•BF3 and (CH3)3N•BH3.

ChemInform Abstract: A High-Yield, General Method for the Catalytic Formation of Oxygen Heterocycles.

ChemInform ◽  
2001 ◽  
Vol 32 (16) ◽  
pp. no-no
Author(s):  
Karen E. Torraca ◽  
Shin-Itsu Kuwabe ◽  
Stephen L. Buchwald
Keyword(s):  
High Yield ◽  
Oxygen Heterocycles ◽  
General Method

scholarly journals The purification and some equilibrium properties of the nitrite reductase of the bacterium Wolinella succinogenes

1986 ◽  
Vol 233 (2) ◽  
pp. 547-552 ◽  
Author(s):  
R Blackmore ◽  
A M Roberton ◽  
T Brittain
Keyword(s):  
High Spin ◽  
Nitrite Reductase ◽  
Reductase Activity ◽  
Spin Transition ◽  
Spectral Characteristics ◽  
High Yield ◽  
Wolinella Succinogenes ◽  
Hydrophobic Binding ◽  
Nitrite Reductase Activity ◽  
Oxygen Reductase

The bacterium Wolinella succinogenes produces a nitrite reductase enzyme that can be purified to homogeneity in high yield by a combination of detergent extraction, hydroxyapatite chromatography and Mr fractionation. Nitrite reductase activity is found to be present in both a high- and a low-Mr fraction. The high-Mr fraction has been shown to consist of the low-Mr nitrite reductase enzyme associated with a hydrophobic ‘binding protein’. The amino acid composition for both proteins is reported. The nitrite reductase enzyme shows spectral characteristics indicative of the presence of c-type haem groups. Measurements at 610 nm indicate the presence of some high-spin haem groups at neutral pH. This haem subgroup undergoes a pH-linked high-spin - low-spin transition at alkaline pH. Approximately two of the six haem groups present within the enzyme bind CO with low affinity (KD = 0.4 mM). The enzyme also shows a range of redox activities with various inorganic reagents. The enzyme has been shown to exhibit dithionite reductase, oxygen reductase and CO2 reductase activities.

Sign in / Sign up

Export Citation Format

Share Document