- Synthetic method of valganciclovir hydrochloride
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The invention discloses a method for synthesizing valganciclovir hydrochloride, which comprises the following steps: with 1,3-dichloro-2-acetoxymethoxypropane as an initial raw material, preparing monochlorinated ganciclovir, and carrying out esterification, hydrolysis and deprotection salification to finally obtain the valganciclovir hydrochloride. The invention provides a synthesis method of siganciclovir hydrochloride, which avoids the problem of separation and conversion of N-7 and N-9 isomers in the diacetyl guanine condensation process. The method directly synthesizes monochlorinated ganciclovir without using ganciclovir, instead of the synthesis of monoacetyl ganciclovir in the prior art, so that the method avoids the problem of diester compound separation caused by ganciclovir residues, has the advantages of short process steps, simple operation, convenient purification and low cost, is beneficial to industrial production, and is suitable for synthesis of valganciclovir hydrochloride.
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Paragraph 0015; 0039; 0040
(2021/04/17)
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- A method for preparing valganciclovir hydrochloride
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The invention discloses a method for preparing valganciclovir hydrochloride I. The method comprises the following steps of: 1, dissolving phosphorus oxychloride into an inert solvent, and performing a reaction of the mixture and the alcoholic liquor to obtain phosphoryl halide II; 2, performing a reaction of ganciclovir and the phosphoryl halide II obtained in the step to obtain ganciclovir monoester III; 3, esterfying the ganciclovir monoester III in the step 2 and N-carbobenzoxy-L-valine to obtain ganciclovir diester IV; 4, acidizing the ganciclovir diester IV in the step 3 for dephosphorylation to obtain N-carbobenzoxy-L-valine ganciclovir monoester V; and 5, performing a hydrogenation reaction on the product in the step 4 to prepare the valganciclovir hydrochloride I. By the method, the ganciclovir monoester with high purity and yield can be produced, the post-processing is easy, and the post-processing difficulty is reduced.
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Paragraph 0018; 0033-0035
(2016/10/08)
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- PREPARATION OF VALGANCICLOVIR AND ITS SALTS
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The application relates to processes for preparing valganciclovir and pharmaceutically acceptable salts thereof, as well as intermediates for the processes. valganciclovir hydrochloride is represented by Formula II.
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Page/Page column 9
(2011/09/16)
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- Preparation of valganciclovir
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A process for the preparation of valganciclovir with triacetyl ganciclovir (V) as a starting material, comprising the following steps: selective hydrolysis, reacting with a coupling agent and a solvent, followed by hydrolysis under basic conditions and hydrogenolysis in the presence of a catalyst.
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Page/Page column 10-11
(2008/06/13)
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- Preparation of ester of purine derivatives
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A process for the preparation of valganciclovir with triacetyl ganciclovir (V) as a starting material, comprising the following steps: selective hydrolysis, reacting with a coupling agent and a solvent, followed by hydrolysis under basic conditions and hydrogenolysis in the presence of a catalyst.
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Page/Page column 7
(2008/06/13)
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- PREPARATION OF ESTERS OF PURINE DERIVATIVES
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The present invention relates to the preparation of esters of purine derivatives and enantiomerically pure esters of purine derivatives or pharmaceutically acceptable salts thereof.
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Page/Page column 16-17; 21
(2008/06/13)
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