(1R)-(-)-10-CAMPHORSULFONIC ACID, AMMONIUM SALT synthesis

Yield:-

Reaction Conditions:

with ammonia in water;4-methyl-2-pentanone; for 0.5 h;

Steps:

12

Example 12 Extraction of (+)-camphor-10-sulphonic acid from a 10% (+)-camphor-10-sulphonic acid ammonium salt solution with isobutyl methyl ketone in a specific rotational perforator using an entraining gas as the stripping medium (inventive) 21.3 g (90 mmol, M=232.30 g/mol, with a content of 98%) of (+)-camphor-10-sulphonic acid were initially charged in 50 g of water and admixed with 6.5 ml of 32% aqueous ammonia solution (0.1 mol). After stirring for 30 minutes, the excess ammonia and most of the water were drawn off from the clear colourless solution at 40° C. in a water-jet vacuum. The resulting white solid (39.8 g) was dissolved in 209.5 g of water. This 10% salt solution was initially charged in the rotational perforator (FIG. 1) and heated to 80° C. The solvent flask was initially charged with 500 g of isobutyl methyl ketone which were heated to boiling (internal temperature 115-117° C.). 6 1 of nitrogen per hour were passed continuously through the aqueous salt solution. After 66 hours, the extraction was ended and the pale-coloured isobutyl methyl ketone and the aqueous phase were concentrated to dryness. 74% of the (+)-camphor-10-sulphonic acid used was still found in the aqueous phase, 25% in the isobutyl methyl ketone. An ion chromatography analysis of the organic phase showed an ammonium content of <100 ppm.

References:

US2010/210871,2010,A1 Location in patent:Page/Page column 12