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This invention discloses an improved process for the preparation of l-(4'-fluorophenyl)-l,3-dihydro-isobenzofiiran-5 carbonitrile of formula-ll, which is useful for the preparation of citalopram of formula-Ill, a well-known antidepressant available in the market. Process for the preparation of compound of formula-II comprises:(i) Reducing the benzophenone derivative of formula-V with sodium borohydride in alcoholic solvent to get the dihydroxy compound of formula-VIII.(ii) Stylizing the dihydroxy compound of formula-VIII with p-toluenesu!fonic acid in toluene to get the phthalate derivative of formula-I.(iii) Reacting the compound of formula I with copper cyanide in dimethylformamide medium to get the Cano derivative of formula-II after re-crystallization from alcoholic solvent with or without dimethylformamide.Compound of formula-II obtained by this method was of high purity and upon further conversion to citalopram product formed in high yield (80%) and high purity (99%).

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Notices, Deadlines & Correspondence

Patent Information

Application #
Filing Date
22 February 2001
Publication Number
Publication Type
Invention Field
Status
Email
Parent Application
Patent Number
Legal Status
Grant Date
2005-12-19
Renewal Date

Applicants

NATCO PHARMA LTD
NATCO HOUSE, ROAD NO.2, BANJARA HILLS, HYDERABAD 500 033

Inventors

1. PULLA REDDY MUDDASANI
NATCO PHARMA LTDNATCO HOUSE, ROAD NO.2, BANJARA HILLS, HYDERABAD 500 003
2. VENKAIAH CHOWDARY NANNAPANENI
NATCO PHARMA LTDNATCO HOUSE, ROAD NO.2, BANJARA HILLS, HYDERABAD 500 003

Specification

Documents

Application Documents

# Name Date
1 Description_Granted 194522_19-12-2005.pdf 2005-12-19
2 Claims_Granted 194522_19-12-2005.pdf 2005-12-19
3 Abstract_Granted 194522_19-12-2005.pdf 2005-12-19
4 157m2001.jpg 2011-09-02
5 0157-mas-2001 petition.pdf 2011-09-02
6 0157-mas-2001 form-5.pdf 2011-09-02
7 0157-mas-2001 form-3.pdf 2011-09-02
8 0157-mas-2001 form-1.pdf 2011-09-02
9 0157-mas-2001 description (complete).pdf 2011-09-02
10 0157-mas-2001 description (complete)-duplicate.pdf 2011-09-02
11 0157-mas-2001 correspondence-po.pdf 2011-09-02
12 0157-mas-2001 correspondence-others.pdf 2011-09-02
13 0157-mas-2001 claims.pdf 2011-09-02
14 0157-mas-2001 claims-duplicate.pdf 2011-09-02
15 0157-mas-2001 abstract.pdf 2011-09-02
16 0157-mas-2001 abstract.jpg 2011-09-02
17 0157-mas-2001 abstract-duplicate.pdf 2011-09-02
18 157-MAS-2001-RELEVANT DOCUMENTS [14-02-2018(online)].pdf 2018-02-14

ERegister / Renewals

3rd: 21 Feb 2006

From 22/02/2003 - To 22/02/2004

4th: 21 Feb 2006

From 22/02/2004 - To 22/02/2005

5th: 21 Feb 2006

From 22/02/2005 - To 22/02/2006

6th: 21 Feb 2006

From 22/02/2006 - To 22/02/2007

7th: 18 Jan 2007

From 22/02/2007 - To 22/02/2008

8th: 15 Feb 2008

From 22/02/2008 - To 22/02/2009

9th: 24 Feb 2009

From 22/02/2009 - To 22/02/2010

10th: 28 Jan 2010

From 22/02/2010 - To 22/02/2011