Thursday 12 March 2015

Odorless and Efficient Thioacetalization Reaction of Oximes





Chemical Journal of Chinese Universities  2012, Vol. 33 Issue (09): 1969-1972
DOI: 10.3969/j.issn.0251-0790.2012.09.016 http://www.cjcu.jlu.edu.cn/EN/abstract/abstract24471.shtml# http://www.cjcu.jlu.edu.cn/EN/volumn/next.shtml  
Odorless and Efficient Thioacetalization Reaction of Oximes    
YU Hai-Feng1, LIAO Pei-Qiu2
1. School of Chemistry and Life Science, Anshan Normal University, Anshan 114007, China;
2. Department of Chemistry, Northeast Normal University, Changchun 130024, China
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Abstract  Thioacetals are important compounds because they can be considered as both useful protecting groups of carbonyl compounds in the synthesis of multi-functional complex molecules and acyl carbanion equi-valents in C—C bond forming reactions. Since many reactions have been developed to prepare oximes from non carbonyl compounds, to lead to a novel and efficient method for thioacetal preparation, transthioacetalization of oximes has received more and more attention. Unfortunately, the transformation usually suffers from the use of harmful, odorous thiols which can lead to serious safety and environment problems. From the green chemistry point of view, an efficient and odorless transthioacetalization of oximes involving an environment friendly reagent is of great importance and necessity. In this work, using odorless and stable α-oxo ketene dithioacetals 1 as thiol equivalents, the thioacetalization reaction of oximes 2 were studied. In the reaction system of MeCOCl-EtOH(95%) or 4-dodecylbenzenesulfonic acid(DBSA)-H2O, the thioacetalization reaction were carried out in reflux temperature. It is noteworthy that the odor of thiols can not be perceived during either the reaction or workup.
 Odorless and Efficient Thioacetalization Reaction of Oximes[J].
Chemical Journal of Chinese Universities, 2012, 33(09): 1969-1972.
URL:
http://www.cjcu.jlu.edu.cn/EN/10.3969/j.issn.0251-0790.2012.09.016     OR
  http://www.cjcu.jlu.edu.cn/EN/Y2012/V33/I09/1969
  Odorless and Efficient Thioacetalization Reaction of Oximes.pdf (1)


  Odorless and Efficient Thioacetalization Reaction of Oximes.pdf (2)


Anshan Normal University, Anshan 114007, China















Department of Chemistry, Northeast Normal University, Changchun 130024, China - See more at: http://organicsynthesisinternational.blogspot.in/#sthash.dl5jq4SB.dpuf











Friday 6 March 2015

7-allyl-6-hydroxy-indan-1-one...Mom will teach you NMR

Figure US08242291-20120814-C00009


Thermal Claisen rearrangement on 6-allyloxy-indan-1-one,  (III) to obtain 7-allyl-6-hydroxy-indan-1-one, (IV):
  • Formula: C12H12O2
  • Molecular Weight: 188.22200
Synonyms:



http://www.google.com/patents/US8242291
EXAMPLE 2
This example refers to reaction b of the process of the invention.
20 kg of the intermediate of formula (III) prepared as described in example 1 are suspended in 50 l of Dowtherm A under nitrogen flow. In an inert atmosphere, it is heated to approximately 200° C. for approximately 5 hours. Upon completion of the reaction (TLC) a clear red-brown solution is obtained, without the formation of black pitch. The reaction mixture is cooled slowly to 25° C. (a partial precipitation is observed). 100 l (5 volumes) of cyclohexane are added and it is cooled to between 0 and 5° C. for one hour. It is filtered by washing with cyclohexane and dried at reduced pressure and T=45° C. for at least 12 hours. 16.8 kg of yellow solid are obtained which is refluxed in 80 l of toluene in the presence of decolouring carbon. The suspension is filtered, washing it with hot toluene. Part of the solvent is distilled at reduced pressure until the beginning of crystallisation. It is cooled at room temperature and then to between 0 and 5° C. for at least one hour.
The filtered solid is washed with cold toluene and dried at reduced pressure at T=45° C. for at least 12 hours. 15.3 kg of intermediate (IV) are obtained in the form of an almost white solid of quality suitable for continuation of the synthesis.
1H-NMR and mass spectroscopic analyses are performed on part of the product thus obtained, purified by chromatography for analytical purposes (silica gel, 7 parts in volume of heptane—3 parts in volume of ethyl acetate), obtaining the following results:
Electron impact mass: [M+]=188
1H-NMR (500 MHz, CDCl3): δ (ppm)
2.72 ppm, t, J=6 Hz, 2H,  AR C=OCH2 CH2 AR
3.03 ppm, t, J=6 Hz, 2H, AR C=OCH2 CH2 AR
4.03 ppm, d, J=6 Hz, 2H, ARCH2CH=CH2
5.13-5.20, Σd, 2H, ARCH2CH=CH2
5.60 ppm, s, 1H, 0H
5.98-6.10 ppm, m, 1H, CH2CH=CH2
7.13 ppm, d, J=8 Hz, 1H, AR
7.25, d, J=8 Hz, 1H. AR

PREDICT
1H NMR

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6-hydroxy-7-prop-2-enyl-2,3-dihydroinden-1-one NMR spectra analysis, Chemical CAS NO. 320574-77-4 NMR spectral analysis, 6-hydroxy-7-prop-2-enyl-2,3-dihydroinden-1-one H-NMR spectrum




13 C NMR

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6-hydroxy-7-prop-2-enyl-2,3-dihydroinden-1-one NMR spectra analysis, Chemical CAS NO. 320574-77-4 NMR spectral analysis, 6-hydroxy-7-prop-2-enyl-2,3-dihydroinden-1-one C-NMR spectrum

6-hydroxy-7-prop-2-enyl-2,3-dihydroinden-1-one

COSY PREDICT


HMBC PREDICT

................ 
COCK SAYS MOM CAN TEACH YOU NMR


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Khajuraho Group of Monuments is located in India
Khajuraho Group of Monuments
Location of Khajuraho Group of Monuments in India.

Location in Madhya PradeshLocation in Madhya Pradesh

  1. Khajuraho Group of Monuments - Wikipedia, the free ...

    en.wikipedia.org/wiki/Khajuraho_Group_of_Monuments

    The Khajuraho Group of Monuments are a group of Hindu and Jain temples in Madhya Pradesh, India. About 620 kilometres (385 mi) southeast of New Delhi, ...























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