(2S)-N-(2,6-dimethylphenyl)-1-propylpiperidine-2-carboxamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a first vial, Ropivacaine-HCl (8.6 mg), 4-armPEG succinimidyl carbonate (60 mg) and 4-armPEG-SH (60 mg) were dissolved in 250 μL of pH 2.2 buffer. This solution was combined with an equal volume of carbonate buffer (pH 9.7) through a spray kit. Ropivacaine precipitates within the gel upon mixing. The Ropivacaine-loaded TC gel swelled 2-2.5 times its original volume. Ropivacaine precipitates within the gel upon mixing

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: About 3 g of Ropivacaine base was dissolved in 10 mL of water and to this solution was added 50 mL of hot acetone and conc. Hydrochloride acid was added slowly with stirring until pH reaches 2 and heated to reflux until the solution becomes clear solution. 20 mL of acetone was added and the precipitated solid was filtered, washed with acetone and dried to give L-Ropivacaine hydrochloride monohydrate 2.9 g, yield 82% Water content: 5.6% was added slowly heated to reflux until the solution the precipitated solid was filtered washed with acetone dried

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: About 2 g of Ropivacaine base was dissolved in 10 mL of water and 7.3 mL of concentrated hydrochloride acid was added slowly with stirring and 350 mL of acetone was added and kept at about 0° C. for 2 days. The precipitated solid was filtered, washed with acetone, and dried under vacuum at about 35° C. for about 6 hr: 1.8 g; yield 79%; water content of 5.6%. The precipitated solid was filtered washed with acetone dried under vacuum at about 35° C. for about 6 hr

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: About 2 g of Ropivacaine base was dissolved in a mixture of 2.6 mL of concentrated hydrochloride acid and 40 mL of water. The solution was heated to about 85° C. and stirred for about 30 min to get a clear solution and cooled to about 5° C. and continued stirring for about 2 hr. A precipitated solid was recovered and filtered, then washed with acetone and dried under vacuum at about 35° C. for about 6 hr. Results: wt 2.0 g, yield 88.5 %; water content: 5.5%. The x-ray diffraction pattern of the material obtained is shown in FIG. 1. to get a clear solution cooled to about 5° C. continued stirring for about 2 hr A precipitated solid was recovered filtered washed with acetone dried under vacuum at about 35° C. for about 6 hr Results The x-ray diffraction pattern of the material obtained

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: About 2 g of Ropivacaine base was dissolved in a mixture of 2.6 mL of concentrated hydrochloride acid and 5 mL of water at about 30° C. This mixture was stirred at a temperature of about 50° C. for about 30 min and then hot acetone (100 ml) was added. The mixture was then held at about 0 to 5° C. and stirring continued for about 2 hr. A precipitated solid was filtered, washed with acetone, and then dried under vacuum at about 35° C. for about 6 hr. 2.1 g, yield 93%, water content: 5.5%. All water contents herein are determined by Karl Fisher titration. was then held at about 0 to 5° C. stirring continued for about 2 hr A precipitated solid was filtered washed with acetone dried under vacuum at about 35° C. for about 6 hr

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: About 2 g of Ropivacaine base was dissolved in a mixture of 2.6 mL of concentrated hydrochloride acid and 5 mL of water at about 30° C. This mixture was stirred at a temperature of about 50° C. for about 30 min and then hot acetone (100 ml) was added. The mixture was then held at about 0 to 5° C. and stirring continued for about 2 hr. A precipitated solid was filtered, washed with acetone, and then dried under vacuum at about 35° C. for about 6 hr. 2.1 g, yield 93%, water content: 5.5%. All water contents herein are determined by Karl Fisher titration. was then held at about 0 to 5° C. stirring continued for about 2 hr A precipitated solid was filtered washed with acetone dried under vacuum at about 35° C. for about 6 hr

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Under stirring, 126 g of ropivacaine tartrate were dissolved in 200 ml of water. To the resulting solution was added a solution of sodium hydroxide 1N, adjusting the pH of the solution around 10. During the addition of the alkaline solution, occurs the precipitation of raw base ropivacaine. The solid is filtered, washed in about 100 ml of distilled water and taken to the stove for drying. MP=142°-145° C., m=70 g (η=85.9%), [α]D25=−74.6° (c=2, MeOH). During the addition of the alkaline solution the precipitation of raw base ropivacaine The solid is filtered washed in about 100 ml of distilled water for drying