There is provided a compound having a structure represented by the following Formula (1), ##STR00001## in Formula (1), R.sub.1 and R.sub.2 each independently represent a phenyl group having a substituent or an unsubstituted phenyl group, R.sub.3 and R.sub.4 each independently represent a C2-C12 alkyl group having a substituent or an unsubstituted C2-C12 alkyl group, a cyano group, a trifluoromethyl group, or a halogen atom, R.sub.5 and R.sub.6 each independently represent a hydrogen atom or an alkyl group, R.sub.7 represents a phenyl group having a substituent, an unsubstituted phenyl group, or a heteroaromatic group having a specific structure, and X.sup.? represents an anion, and in a case where at least one anionic substituent is included in a molecule, X.sup.? may not be present.

Isosulfan blue and processes for the preparation thereof are provided. A process is also provided for preparation of the intermediate, 2-chlorobenzaldehyde-5-sulfonic acid, sodium salt of formula (2), used in the preparation thereof and a procedure for the isolation of benzaldehyde-2,5-disulfonic acid, di-sodium salt of the formula (3). Also provided is a process for the preparation of an isoleuco acid of formula (4), which upon oxidation gives rise to isosulfan blue of pharmaceutical grade which can be used for preparation of pharmaceutical formulations. The isolation and purification procedures provided in the process provide substantially pure isosulfan blue with HPLC purity 99.5% or greater.

Isosulfan blue and processes for the preparation thereof are provided. A process is also provided for preparation of the intermediate, 2-chlorobenzaldehyde-5-sulfonic acid, sodium salt of formula (2), used in the preparation thereof and a procedure for the isolation of benzaldehyde-2,5-disulfonic acid, di-sodium salt of the formula (3). Also provided is a process for the preparation of an isoleuco acid of formula (4), which upon oxidation gives rise to isosulfan blue of pharmaceutical grade which can be used for preparation of pharmaceutical formulations. The isolation and purification procedures provided in the process provide substantially pure isosulfan blue with HPLC purity 99.5% or greater.

Provided is a compound which accelerates the enzymatic reaction catalyzed by an oxidase. The present invention provides an oxidase reaction accelerating agent comprising a compound represented by formula (I) and a method using the same.

Provided is an improved process for the preparation N-[4-[[4-(diethyl amino) phenyl](2,5-disulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-N-ethylethanaminium inner salt sodium salt (Isosulfan blue) of formula I. It also relates to highly pure novel crystalline form of Isosulfan blue hydrate and its process for the preparation thereof. It also relates to an improved process for the preparation of Isosulfan blue sodium hydrate having not more than 0.2% of desethyl impurity of formula A.

##STR00001##

Provided is an improved process for the preparation N-[4-[[4-(diethyl amino) phenyl](2,5-disulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-N-ethylethanaminium inner salt sodium salt (Isosulfan blue) of formula I. It also relates to highly pure novel crystalline form of Isosulfan blue hydrate and its process for the preparation thereof. It also relates to an improved process for the preparation of Isosulfan blue sodium hydrate having not more than 0.2% of desethyl impurity of formula A.

##STR00001##

A compound is represented by the following formula (1). ##STR00001##
In the compound represented by Formula (1), at least one of R.sub.1 to R.sub.24 is a group particularly high electron withdrawing property, such as a sulfonic acid group and a carboxylic acid group or a group having the next highest electron withdrawing property to the sulfonic acid group and the carboxylic acid group, such as a halogen atom.

A compound is represented by the following formula (1). ##STR00001##
In the compound represented by Formula (1), at least one of R.sub.1 to R.sub.24 is a group particularly high electron withdrawing property, such as a sulfonic acid group and a carboxylic acid group or a group having the next highest electron withdrawing property to the sulfonic acid group and the carboxylic acid group, such as a halogen atom.

Isosulfan blue and processes for the preparation thereof are provided. A process is also provided for preparation of the intermediate, 2-chlorobenzaldehyde-5-sulfonic acid, sodium salt of formula (2), used in the preparation thereof and a procedure for the isolation of benzaldehyde-2,5-disulfonic acid, di-sodium salt of the formula (3). Also provided is a process for the preparation of an isoleuco acid of formula (4), which upon oxidation gives rise to isosulfan blue of pharmaceutical grade which can be used for preparation of pharmaceutical formulations. The isolation and purification procedures provided in the process provide substantially pure isosulfan blue with HPLC purity 99.5% or greater.

Isosulfan blue and processes for the preparation thereof are provided. A process is also provided for preparation of the intermediate, 2-chlorobenzaldehyde-5-sulfonic acid, sodium salt of formula (2), used in the preparation thereof and a procedure for the isolation of benzaldehyde-2,5-disulfonic acid, di-sodium salt of the formula (3). Also provided is a process for the preparation of an isoleuco acid of formula (4), which upon oxidation gives rise to isosulfan blue of pharmaceutical grade which can be used for preparation of pharmaceutical formulations. The isolation and purification procedures provided in the process provide substantially pure isosulfan blue with HPLC purity 99.5% or greater.