- A method for preparing the levamisole hydrochloride
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The invention discloses a preparation method for levamisole hydrochloride, with low energy consumption, no wastewater, stable quality and high yield. The preparation method takes use of L-tetramisole as a raw material and comprises the steps of dissolving L-tetramisole in isopropanol; adding an antioxidant; decoloring with activated carbon; filtering; introducing a hydrogen chloride gas under stirring; controlling a pH value at an end point to be 4-5; and separating after reaction is finished, thus obtaining a finished product of levamisole hydrochloride. According to the preparation method, a novel better solvent of isopropanol is used in a salifying step. Isopropanol has a boiling point higher than that of acetone, low volatility, small system loss, high recovery rate and low unit consumption, and saves cost. The preparation technology is in no need of steaming water, has small wastewater discharge, produces no wastewater and has low energy consumption. The preparation technology omits a high temperature steaming water process; a product does not cake, has no generation of yellow spot, guarantees the quality of prepared levamisole hydrochloride, and has high yield. By adding the antioxidant, the quality stability of the product is increased; and the product has good appearance.
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Paragraph 0021; 0022
(2017/03/08)
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- Pesticidal compositions in paste form
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Novel pasty compositions for the control of animal pests and fungal diseases on plants, which compositions comprise at least one pesticidally active or fungicidally active compound and at least one adjuvant, which is solid, liquid or pasty at room temperature and optionally, one or more excipients and water.
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- Process for isolating levamisole from tetramisole
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A process for isolating levamisole or a therapeutically acceptable acid addition salt thereof from tetramisole or an acid addition salt thereof by precipitating levamisole. L-N-[(4-methoxyphenyl)sulfonyl]-glutamic acid (salt) and converting the diastereomeric salt into levamisole or a suitable acid addition salt thereof.
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- Process for formulating a synthetic drug for use in animal feed, and resulting formulation
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A method of formulating a synthetic drug for use in animal feed, for the purpose of reducing carry-over of the synthetic drug to subsequent lots of animal feed in the feed mill.
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- A CONVENIENT METHOD FOR OPTICAL RESOLUTIONS VIA DIASTEREOISOMERIC SALT FORMATION
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With the advantage of the method using two immiscible solvents and half-equivalent amount of the resolving agent, higher optical purity can be obtained than in cases of any other resolution via diastereoisomeric salt formation, besides it is a faster procedure for resolution of a new racemate as well.
- Acs, M.,Fogassy, E.,Faigl, F.
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p. 2465 - 2470
(2007/10/02)
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