Reusable transition metal complex catalyst useful for the preparation of high pure quality 3,3′-diaminobenzidine and its analogues and a process thereof

US7999112B2 · kind B2 · utility

Assignee

• COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH · IN

Inventors

• Ravi Shukla · Columbia, US
• Lourduswamy Emmanuvel · Jamkhed, IN
• Chidambaram Rameshkumar · Jamkhed, IN
• Suryavanshi Gurunath · Jamkhed, IN
• Arumugam Sudalai · Pune, IN
• Swati KULKARNI · Thane, IN
• Swaminathan Sivaram · Pune, IN

Key dates

• Filing date: Mar 11, 2008
• Grant date: Aug 16, 2011
• Expiry date: Sep 27, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F15/008
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention provides a reusable transition metal complex catalyst useful for the preparation of high pure quality 3,3′-diaminobenzidine and its analogues. The present invention also provides to a process for the preparation of a reusable transition metal complex catalyst. The present invention further provides a process for the preparation of 3,3′-diaminobenzidine (DAB) or 3,3′,4,4′ Tetraminobiphenyl (TAB) using reusable transition metal complex catalyst. The high quality 3,3′-diaminobenzedine (DAB) and its analogues are prepared by coupling 4-halo-2-nitroaniline to 3,3′-dinitrobenzidine (DNB) using transition metals as catalysts followed by reduction of 3,3′-dinitrobenzidine to the corresponding substituted 3,3′-diaminobenzidine of formula 1 in high yields.