Process for the manufacture of 3′-hydroxy pterostilbene

Patent metadata

Field	Value
Publication number	US-9458075-B1
Application number	US-201514718088-A
Country	US
Kind code	B1
Filing date	May 21, 2015
Priority date	May 21, 2015
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

The invention discloses high yielding synthetic process for 3′-hydroxy pterostilbene.

First claim

We claim:

1. A process for the synthesis of 3′-hydroxy pterostilbene, said process comprising steps of:
a) Orthoformylation of pterostilbene by using anhydrous magnesium chloride, triethylamine and paraformaldehyde to obtain 3′-formyl pterostilbene; and
b) Subjecting 3′-formyl pterostilbene obtained in step (a) to Dakin oxidation using hydrogen peroxide in sodium hydroxide to form 3′-hydroxy pterostilbene.

2. The process as claimed in claim 1 , wherein said process comprises steps of:
a. Adding at room temperature, paraformaldehyde, triethylamine and anhydrous magnesium chloride to a solution of pterostilbene in acetonitrile;
b. Stirring the solution of step (a) at reflux temperature and monitoring using thin layer chromatography (TLC);
c. Upon disappearance of substrates, adding to step b, water and further acidifying with dilute hydrochloric acid;
d. Extracting the reaction mixtures of step c with dichloromethane;
e. Washing the organic phases of the extract of step d with water and further drying on sodium sulfate;
f. Evaporation of the extract of step e to remove organic solvents under reduced pressure to obtain crude 3′-formyl pterostilbene;
g. Adding isopropyl alcohol (IPA) to crude 3′-formyl pterostilbene of step f to obtain pure 3′-formyl pterostilbene as solid;
h. Adding solution of sodium hydroxide at room temperature to a solution of 3′-formyl pterostilbene and hydrogen peroxide from step g in THF and water;
i. Stirring the solution of step h at room temperature for 1 hour and monitoring the reaction by TLC;
j. Upon disappearance of substrates, adding to step i, water and further acidifying with dilute hydrochloric acid;
k. Extracting the reaction mixtures of step j with dichloromethane;
l. Washing the organic phases of the extract of step k with sodium thiosulphate, water and further drying on sodium sulphate;
m. Evaporation of the extract of step 1 to remove organic solvents under reduced pressure to obtain crude 3′-hydroxypterostilbene; and
n. Crystallizing crude 3′-hydroxypterostilbene of step m to obtain solid final product.

Assignees

• Majeed Muhammed
• Nagabhushanam Kalyanam
• Ganjihal Savita S
• Sami Labs Ltd

Inventors

• Majeed Muhammed
• Nagabhushanam Kalyanam
• Ganjihal Savita S

Classifications

• C07C45/00

  Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds · CPC title

• C07C41/26 Primary

  by introduction of hydroxy or O-metal groups · CPC title

• C07C47/575

  containing ether groups, [IMAGE cpc-sch-C07C-0958.gif] groups,[IMAGE cpc-sch-C07C-0959.gif] groups, or[IMAGE cpc-sch-C07C-0960.gif] groups · CPC title

• C07C43/23

  containing hydroxy or O-metal groups · CPC title