1041-01-6Relevant articles and documents
Preparation method of levothyroxine sodium
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, (2019/06/05)
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.
Reductive dehalogenation and dehalogenative sulfonation of phenols and heteroaromatics with sodium sulfite in an aqueous medium
Tomanová, Monika,Jedinák, Luká?,Canka?, Petr
supporting information, p. 2621 - 2628 (2019/06/03)
Prototropic tautomerism was used as a tool for the reductive dehalogenation of (hetero)aryl bromides and iodides, or dehalogenative sulfonation of (hetero)aryl chlorides and fluorides, using sodium sulfite as the sole reagent in an aqueous medium. This protocol does not require a metal or phase transfer catalyst and avoids using organic solvent as the reaction medium. This method is especially suitable for substrates that readily tautomerize (such as 2-or 4-halogenated aminophenols and 4-halogenated resorcinols), for which dehalogenation or sulfonation proceeds under mild reaction conditions (≤60 °C). As sodium sulfite is an inexpensive, safe, and environmentally less hazardous reagent, this method has at least three potential applications: (i) in the deprotection of halogens as protecting groups, using sodium sulfite as a reducing agent; (ii) in the sulfonation of aromatic halides under mild reaction conditions avoiding hazardous and corrosive reagents/solvents; and (iii) in the transformation of toxic halogenated aromatics into less harmful compounds.
A concise synthesis of thyroxine (T4) and 3,5,3'-Triiodo-L-thyronine (T3)
Salamonczyk, Grzegorz M.,Oza, Vibha B.,Sih, Charles J.
, p. 6965 - 6968 (2007/10/03)
The mono- and di-iodo derivatives of 1-oxaspiro[2,5]bicycloocta-4,7-dien-6-one, 8 and 9, reacted readily with 3,5-diiodo-L-tyrosine at pH 8.0 to give 3,5,3'-triiodo-L-thyronine (T3) and thyroxine in 70% and 94% yields respectively. In turn, 8 and 9 were prepared by the sodium bismuthate oxidation of their corresponding iodinated p-hydroxybenzyl alcohol derivatives, 6 and 7 in 32% and 37% yields.