- A 2, 5 - furan two alkoxyl dihydro preparation method of compound
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The invention provides a preparation method of a 2,5-dialkoxyl dihydrofuran compound. The preparation method comprises the following steps: adding a furan compound shown by a formula I, alkyl alcohol shown by a formula III and an acid-binding agent into a reactor, stirring to react with chlorine, keeping the reaction temperature to be (-25)-25 DEG C, and reacting to obtain a 2,5-dialkoxyl dihydrofuran compound shown by a formula II, wherein in the formulas, R1, R2, R3 and R4 are independent hydrogen, halogen and C1-C5 alkyl, and R1 is a C1-C12 alkyl. The method provided by the invention is less in investment, low in energy consumption and high in efficiency; the reaction method is simple, and the operation is convenient and easy to implement; the raw materials are low in price, easy to obtain, and low in production cost; a byproduct is salt and can meet requirements on environmental protection; and the preparation method is suitable for performing industrial large-scale production of the 2,5-dialkoxyl dihydrofuran compound. Particularly, when a phase transfer catalyst is added into the method provided by the invention, the method also has the advantage that the yield of a target product is obviously improved.
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Paragraph 0025; 0026
(2017/08/25)
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- NEUROLOGICALLY-ACTIVE COMPOUNDS
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The invention provides a compound of the formula (I): wherein R is methyl, ethyl, propyl, isopropyl, butyl, pentyl, neo-pentyl or cyclohexyl, or a salt or solvate thereof. These compounds are selective GABAC receptor antagonists. The invention also provides pharmaceutical compositions comprising a compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof. The invention also provides methods of enhancing the cognitive activity of an animal and methods of stimulating memory capacity in an animal, comprising the step of administering to the animal an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof.
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Page/Page column 10; 18
(2008/06/13)
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- Five-membered ring analogues of shikimic acid
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Shikimate and other intermediates of the shikimate-chorismate pathway are densely functionalized structures that seem to offer limited options for skeletal modification. We designed and synthesized cyclopentylidenes 1 and 2, as well as cyclopentenes 3 and 4, as novel ring-contracted analogues of shikimic acid. Enzymatic studies showed that analogues 1-3 are indeed processed by shikimate kinase to give phosphates 1-P, 2-P, and 3-P as five-membered ring analogues of shikimate-3-phosphate. In particular, analogue 1 is converted by the enzyme at a rate only 3.5-fold slower than that of the native substrate, while analogue 3 binds to shikimate kinase with an apparent Km of 1.7 mM, compared to 0.14 mM for shikimate.
- An,Toochinda,Bartlett
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p. 1326 - 1333
(2007/10/03)
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- A Novel Synthesis of rac-5-(Hydroxymethyl)-1-(Tetrahydro-2'-oxofur-3'-yl)-1H-pyrrole-2-carboxaldehyde
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A novel six-step synthesis of rac-5-(hydroxymethyl)-1-(tetrahydro-2'-oxofur-3'-yl)-1H-pyrrole-2-carboxaldehyde (rac-1) starting from 2-methylfuran has been developed.The key step is the formation of rac-2-methyl-1-(tetrahydro-2'-oxofur-3'-yl)-1H-pyrrole (rac-7) according to the Clauson-Kaas procedure.Subsequent Vilsmeier formylation, oxidation with lead tetraacetate, and enzymatic hydrolysis led to rac-1.
- Hayoz, Pascal,Aeby, Anton,Pasquier, Cecile,Neier, Reinhard
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p. 230 - 232
(2007/10/02)
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- Intermediates for synthesizing BH4 and its derivatives
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The present invention relates to intermediates for synthesizing BH4 and derivatives thereof. The intermediates are shown as follows: STR1 wherein R1 is a hydrogen atom, alkyl, aralkyl, or aryl group; R2 is an alkyl, hydroxyalkyl, or polyhydroxyalkyl group; R3 and R4 are the same or different and represent alkyl, aralkyl, or aryl group; R5, R6, R7, and R8 are the same or different and represent a hydrogen atom or acyl group; R9 is an alkyl, aralkyl, or aryl group; R10 and R11 are the same or different and represent a hydrogen atom or acyl group; n is an integer of 5 or less; and HX is an acid. The invention also relates to a process for the preparation of L-biopterin.
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- A PHOTO-OXIDATIVE ANALOGUE OF THE CLAUSON-KAAS REACTION
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2,5-Dimethoxy-2,5-dihydrofurans and spiroketals are obtained upon V2O5-catalysed degradation of hydroperoxides formed in furan photo-oxidations.
- Feringa, Ben L.,Butselaar, Robert J.
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p. 1941 - 1942
(2007/10/02)
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