Abstract: Provided herein is a process for preparation of 3,7-bis-(dimethylamino)-phenothian-5-ium chloride: Formula (I). The said process comprises preparing 3,7-dibromophenothiazin-5-ium bromide wet Crude(III) from phenothiazine (II) along promoter, catalyst and brominating agent in presence of organic solvent; preparing 3,7-bis-(dimethylamino)-phenothiazin-5-ium bromide (IV) from 3,7-dibromophenothiazin-5-ium bromide; preparing 3,7-bis (Dimethylamino)-phenothiazin-5-ium chloride from 3,7-bis-(dimethylamino)-phenothiazin-5-ium bromide and subsequently purifying and removing metal content through metal scavenger from 3,7-bis-(dimethylamino)-phenothiazin-5-ium chloride (I). The present process eliminates the additional step of ion exchange column in the reaction and provides 99 to 99.5 percentage of product purity.

Abstract: The present invention discloses Octenidine based compounds of formula (A) or formula (B) and formula (C) where in, n=1, 2, 3, 4 and R?=un-substituted or substituted aryl or alkyl group; R is hydroxy or hydrogen, X is chlorine, bromine and iodine. The present invention also relates to a process for the preparation thereof.

Abstract: The present invention discloses Octenidine based compounds of formula (A) or formula (B) and formula (C) where in, n=1,2,3,4 and R?=un-substituted or substituted aryl or alkyl group; R is hydroxy or hydrogen, X is chlorine, bromine and iodine. The present invention also relates to a process for the preparation thereof.

Abstract: The present invention relates to an improved process for preparation of Indigo carmine of Formula (I), in high purity, more than 99.5%.

Abstract: The present invention relates to process for preparation of Isosulfan blue (Formula I) substantially free from desethyl impurity.

Abstract: The present invention involves an improved process for the preparation of Indocyanine green of Formula (I) having high purity of about 99%, wherein the process comprises steps of reacting 1,1,2-trimethyl-1H-benzo[e]indole with 1,4-butane sulfone in boiling solvent to give 4-(1,1,2-trimethyl-1H-benzo[e]indolium-3-yl)butane-1-sulfonate. Followed by reacting 4-(1,1,2-trimethyl-1H-benzo[e]indolium-3-yl)butane-1-sulfonate of Formula (IV) and N-phenyl-N-((1E,3E,5E)-5-(phenylimino)penta-1,3-dienyl)acetamide of formula (V) in presence of sodium acetate and alcohol; and extracting the title compound formula (I) with an ester solvent.

Abstract: The present invention relates to process for preparation of Isosulfan blue (Formula I) substantially free from desethyl impurity.

Abstract: The present invention involves an improved process for the preparation of Indocyanine green of Formula (I) having high purity of about 99%, wherein the process comprises steps of reacting 1,1,2-trimethyl-1H-benzo[e]indole with 1,4-butane sulfone in boiling solvent to give 4-(1,1,2-trimethyl-1H-benzo[e]indolium-3-yl)butane-1-sulfonate. Followed by reacting 4-(1,1,2-trimethyl-1H-benzo[e]indolium-3-yl)butane-1-sulfonate of Formula (IV) and N-phenyl-N-((1E,3E,5E)-5-(phenylimino)penta-1,3-dienyl)acetamide of formula (V) in presence of sodium acetate and alcohol; and extracting the title compound formula (I) with an ester solvent.

Abstract: The present invention relates to an improved process for preparation of Indigo carmine of Formula (I), in high purity, more than 99.5%.

Abstract: The invention pertains to a process for preparing stable anhydrous Ropivacaine hydrochloride, the process involving preparing Ropivacaine hydrochloride from Ropivacaine base, wherein Ropivacaine base is provided having a chiral purity of more than 95%, and wherein the isolation involves the use of isopropanol and hydrochloride, and is performed under water-free conditions. Ropivacaine base may be provided at high chiral purity by N-propylating L-pipecolic acid 2,6-xylidide hydrochloride in the presence of a phase transfer catalyst, wherein the reaction involves a biphasic reaction mixture containing an alkaline aqueous phase and an organic phase. The invention further pertains to stable anhydrous Ropivacaine hydrochloride obtainable by the above process.

Abstract: The invention relates to a preparation process for 2-substituted 5-formylimidazoles, wherein the intermediate high-pressurized synthesis of an 2-substituted 4-hydroxymethylimidazole as known in the art is conveniently avoided, and wherein much higher yields are obtained. Instead, it is proposed to prepare such 2-substituted 5-formylimidazoles via a one-pot synthesis involving 2-substituted 4-chloro-5-formylimidazole, thereby employing an additional hydrodehalogenation step. Moreover, it is found that the yield and purity of 2-substituted 4-chloro-5-formylimidazole itself can be significantly improved using a triflate catalyst in the preparation process.