Stable formulations of alkyl benzidine compounds and methods of making and using same. To prepare a stable formulation, a short chain diol having fewer than six carbon atoms and an alkyl benzidine compound are combined together in solution at low pH and the solution is heated with moderate heat in the range of about 50 C. to 80 C. The stable formulation may contain dimers and/or trimers of the short chain diol. The stable formulation can be used to detect total chlorine in aqueous solution, to detect total chlorine in dialysis water, or as a colorimetric substrate in enzyme-linked immunosorbent assays.

Stable formulations of alkyl benzidine compounds and methods of making and using same. To prepare a stable formulation, a short chain diol having fewer than six carbon atoms and an alkyl benzidine compound are combined together in solution at low pH and the solution is heated with moderate heat in the range of about 50 C. to 80 C. The stable formulation may contain dimers and/or trimers of the short chain diol. The stable formulation can be used to detect total chlorine in aqueous solution, to detect total chlorine in dialysis water, or as a colorimetric substrate in enzyme-linked immunosorbent assays.

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 method of preparing isosulfan blue.

Provided is a method of preparing isosulfan blue.

Provided is a method of preparing isosulfan blue.

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.

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.