Processes for preparing novel methylene blue derivative

• US 7,176,308 B2
• Filed: 11/17/2003
• Issued: 02/13/2007
• Est. Priority Date: 06/17/2002
• Status: Expired due to Fees

• Current Assignee: Verification Technologies, Inc. (Sun Chemical, Inc.)
• Original Assignee: Verification Technologies, Inc. (Sun Chemical, Inc.)
• Inventors: Miller, Peter, Vig, Rakesh, Selinfreund, Richard H., Gerger, Scott, Cook, Ewell, Phillips, Chris, Cunningham, Mike, Saglimbeni, Anthony A.
• Primary Examiner(s): Habte; Kahsay
• Application Number:
  US10/715,226
• Publication Number:
  US 20050107607A1
• Time in Patent Office: 1,184 Days
• Field of Search: 544/37
• US Class Current: 544/37
• CPC Class Codes: C07D 279/18 [b, e]-condensed with two six-membered rings

Abstract

Methods for the preparation of 7-(dipropylamino)pheno-thiazin-3-ylidene]-dipropylamine.

Claims

1. A method of the synthesis of [7-dipropylamino) phenothiazin-3-ylidene]dipropylarnine comprising the step of reacting 3,7-dibromophenothiazine-5-ium bromide with dipropylamine in the presence of copper.

2. A method for isolating [7-dipropylamino) phenothiazin-3-ylidene]dipropylamine from an impure mixture comprising the steps of:

(a) dissolving the impure mixture in hot water;

(b) filtering the hot solution of step (a) to remove insoluble matters;

(c) treating the hot filtrate of step (b) with ZnCl₂ to precipitate the ZnCl₂ salt;

(d) dissolving the ZnCl₂ salt in a base;

(a) washing the filtrate of step (d) with an organic solvent and treating the same with a salt to precipitate [7-dipropylamino) phenothiazin-3-ylidene]dipropylamine.

3. A method for the synthesis of [7-(dipropylamino)phcnothiazin-3-ylidene]dipropylamine comprising the step of reacting phenothiazine or any salt thereof with dipropyl amine in the presence of copper.