- Preparation method of levothyroxine sodium
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The invention belongs to the field of pharmaceutical synthesis, and discloses a preparation method of levothyroxine sodium. The preparation method comprises the following steps: (1) taking 3,5-diiodo-L-tyrosine as a raw material, and preparing N-acetyl-L-tyrosine by firstly introducing acetyl protection to an amino group; (2) then preparing N-acetyl-3,5-diiodo-L-tyrosine ethyl ester under the action of thionyl chloride; (3) preparing N-acetyl-O-(4-methyoxyphenyl)-3,3-diiodo-L-tyrosine ethyl ester by carrying out Chan-Lam reaction through copper catalysis; (4) removing a protective group undera strong acidity condition, thus obtaining O-(4-hydroxyphenyl)-3,5-diiodo-L-tyrosine; (5) then reacting with iodine, and preparing O-(4-hydroxy-3,5-diiodo phenyl)-3,5-diiodo-L-tyrosine disodium salt under the action of sodium hydroxide; (6) finally, regulating pH (Potential of Hydrogen) through glacial acetic acid, thus obtaining the levothyroxine sodium. According to the preparation method disclosed by the invention, the key Chan-Lam reaction and other reaction steps are optimized, so that the reaction time can be greatly shortened, and the reaction yield can be increased; the preparation method is simple in technology, convenient to operate and suitable for industrial production.
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- Improved method for synthesizing L-thyroxine sodium
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The invention relates to an improved method for synthesizing L-thyroxine sodium. The improved method includes the steps that 3,5-diiodomethane-L-tyrosine is used as a raw material, and then subjectedto a copper complex reaction, a coupling reaction, an acid hydrolysis reaction, an iodine generation reaction and a salt forming reaction to obtained the L-thyroxine sodium. According to the improvedmethod for synthesizing the L-thyroxine sodium, the yield of the L-thyroxine sodium can be improved, the product cost is lowered, and industrialization is convenient.
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- A PROCESS FOR PREPARATION OF LEVOTHYROXINE AND SALTS THEREOF
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The present invention relates to a process for the preparation of Levothyroxine and salts thereof. The process described in the present invention provides increase in the yields and purity comprising the use of sodium iodide and sodium hypochlorite as iodinating agent.
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- NOVEL PROCESS FOR THE PREPARATION OF LEVOTHYROXINE SODIUM
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The present invention provides a novel process for the preparation of highly pure Levothyroxine Sodium, i.e., (S)-2-amino-3-[4-(4-hydroxy-3, 5-diiodophenoxy)-3,5- diiodophenyl] propanoic acid sodium salt via two process intermediates viz 3,5-Diiodo L- Tyrosine copper complex and novel Bis (p-anisyl) iodonium lodide.The invention also provides levothyroxine pentahydrate free from genotoxic impurities and liothyronine levels below 0.04% wt/wt.
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- Process for the preparation of thyroid hormones and derivatives thereof
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The present invention generally refers to a process for the preparation of L-thyroxine derivatives. More in particular, the present invention relates to a iodination reaction of an aromatic derivative with an appropriate iodinating agent, so to afford the related iodinated compound as disodium salt, which may represent a useful intermediate for the synthesis of the L-thyroxine mono-sodium salt, and the free form thereof.
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Page/Page column 6
(2011/07/09)
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- PROCESS FOR THE PREPARATION OF THYROID HORMONES AND SALTS THEREOF
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The present invention generally refers to a process for the preparation of L- thyroxine derivatives. More in particular, the present invention relates to a iodination reaction of an aromatic derivative with an appropriate iodinating agent, so to afford the related iodinated compound as disodium salt, which may represent a useful intermediate for the synthesis of the L-thyroxine mono-sodium salt, and the free form thereof.
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Page/Page column 13
(2011/07/07)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF LEVOTHYROXINE SODIUM WITH REDUCED LEVELS OF IMPURITIES
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The invention relates to an improved process for the preparation of Levothyroxine sodium with reduced levels of impurities. The invention also provides Levothyroxine sodium pentahydrate free from 3,5-Diiodothyronine or d-enantiomer of thyroxine. The invention also provides Levothyroxine sodium pentahydrate having liothyronine below 0.5% wt / wt.
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Page/Page column 5
(2010/01/29)
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