2867-59-6Relevant articles and documents
Substituent effects in the ring-chain tautomerism of 4-alkyl-2-aryl substituted oxazolidines and tetrahydro-1,3-oxazines
Juhasz, Marta,Lazar, Laszlo,Fueloep, Ferenc
, p. 1465 - 1473 (2007)
(Chemical Equation Presented) The condensation products of 2-aminoethanol or 3-aminopropanol (bearing an alkyl substituent on the carbon adjacent to the nitrogen) with substituted benzaldehydes proved to exist in CDCl3 at 300 K as three-component tautomeric mixtures of the diastereomeric five- or six-membered 1,3-O,N-heterocyclic ring forms and the corresponding imines. For each equilibrium, the electronic effects of the 2-aryl substituents were characterized by the Hammett equation. The steric effects of the alkyl groups could be described by Hansch-type equations for the equilibria involving oxazolidine ring forms. While the alkyl substituents did not cause any significant effect on the ring cis-chain and the ring trans-chain equilibria for tetrahydro-1,3-oxazines, increasing bulk of the 4-alkyl group increased the stability of the cyclic tautomers for the analogous oxazolidines.
Six-Step Gram-Scale Synthesis of the Human Immunodeficiency Virus Integrase Inhibitor Dolutegravir Sodium
Dietz, Jule-Philipp,Lucas, Tobias,Gro?, Jonathan,Seitel, Sebastian,Brauer, Jan,Ferenc, Dorota,Gupton, B. Frank,Opatz, Till
, p. 1898 - 1910 (2021/08/01)
A short and practical synthesis for preparing the active pharmaceutical ingredient dolutegravir sodium was developed. The convergent strategy starts from (R)-3-amino-1-butanol and establishes the BC ring system in a 76% isolated yield over four steps. Ring A was constructed by a one-pot 1,4-addition to diethyl-(2E/Z)-2-(ethoxymethylidene)-3-oxobutandioate and subsequent MgBr2·OEt2-mediated regioselective cyclization. Amide formation with 2,4-difluorobenzylamine was either performed from the free carboxylic acid or through aminolysis of the corresponding ethyl ester. Final salt formation afforded dolutegravir sodium in a 48-51% isolated yield (HPLC purity of 99.7-99.9%) over six linear steps.
Method for preparing (R)-3-aminobutanol
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Paragraph 0068-0077, (2020/01/25)
The invention provides a method for preparing (R)-3-aminobutanol, and the method comprises the following steps of: (1) providing 4-hydroxy-2-butanone and carrying out ammoniation reduction on the 4-hydroxy-2-butanone to obtain racemic 3-aminobutanol; (2) reacting (S)-mandelic acid with the racemic 3-aminobutanol to obtain resolved mandelic acid salt; and (3) alkalizing the resolved mandelic acid salt to obtain the product (R)-3-aminobutanol. According to the invention, the process of preparing the (R)-3-aminobutanol through reductive amination and salification resolution is simple and convenient to operate, low in reaction danger and pollution; the purity of the obtained (R)-3-aminobutanol reaches 99.9% (GC method).
An improved preparation of (R)-3-aminobutanol, a key intermediate for the synthesis of dolutegravir sodium
Srinivasa Rao,Hari Babu,Aminual,Nageshwar,Satyanarayana
, p. 1371 - 1375 (2017/12/28)
Background: Dolutegravir sodium is a HIV-1 integrase strand transfer inhibitor (INSTI) and in combination with other anti-retroviral agents, is recommended for the treatment of HIV-1 infection. Moreover, it is a second generation HIV integrase inhibitor d