Hydrobromic acid hbr

Example 25

7.21 g of solid lactide (0.05 mol, L,L lactide, polymer grade, Corbion Purac Co., Lenexa, Kans.) were mixed with 50.57 g of 48 wt % hydrobromic acid (HBr; 0.3 mol, 48%; Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany; catalog #244260) in a 100 mL three-necked glass reactor in said molar ratio of 1:3 at room temperature and atmospheric conditions. The reaction mixture was heated to 90° C. under continuous stirring with a magnetic stirring bar at a speed of 300 rpm. The reaction mixture was batchwise refluxed and gaseous by-products were routed to the off-gas or collected in a hydrostatic column. After a reaction time of 24 hours, the hot solution was allowed to cool down to RT. The aqueous reaction phase was analyzed via off-line ¹H NMR (JEOL ECX 400 MHz). ¹H qNMR analysis of the reaction mixture gave a 2-BrPA yield of about 5 mol % and selectivity of about 71 mol %.

Example 28

10.24 g of an 88 wt % L-lactic acid solution (0.1 mol, Corbion Purac Co., Lenexa, Kans.) were mixed with 50.57 g of 48 wt % hydrobromic acid (HBr; 0.3 mol, 48%; Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany; catalog #244260) in a 250 mL three-necked glass reactor at room temperature and atmospheric conditions. 33.70 g of chlorobenzene (0.3 mol, anhydrous, 99.8%, Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany; catalog #284513) were added to isolate the formed product. The biphasic reaction mixture was heated to 113° C. under continuous stirring with a magnetic stirring bar at a speed of 300 rpm. The biphasic reaction mixture was batchwise refluxed and gaseous by-products were routed to the off-gas or collected in a hydrostatic column. After a reaction time of 24 h, the hot solution was allowed to cool down to room temperature and the two phases were separated with a separating funnel. The aqueous reaction phase, as well as the organic extraction phase, were both analyzed via off-line ¹H NMR (JEOL ECX 400 MHz). ¹H qNMR analysis of the reaction mixture gave a 2-BrPA yield of about 28 mol % and selectivity of about 54 mol %. Similar experiments with: a) toluene produced 2-BrPA yield of about 12 mol % and selectivity of about 65 mol % at 100° C.; and b) bromobenzene produced 2-BrPA yield of about 29 mol % and selectivity of about 40 mol % at 120° C.

Example 24

7.21 g of solid lactide (0.05 mol, L,L lactide, polymer grade, Corbion Purac Co., Lenexa, Kans.) were mixed with 50.57 g of 48 wt % hydrobromic acid (HBr; 0.3 mol, 48%; Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany; catalog #244260) in a 100 mL three-necked glass reactor in said molar ratio of 1:3 at room temperature and atmospheric conditions. The reaction mixture was heated to 100° C. under continuous stirring with a magnetic stirring bar at a speed of 300 rpm. The reaction mixture was batchwise refluxed and gaseous by-products were routed to the off-gas or collected in a hydrostatic column. After a reaction time of 72 hours, the hot solution was allowed to cool down to RT. The aqueous reaction phase was analyzed via off-line ¹H NMR (JEOL ECX 400 MHz). ¹H qNMR analysis of the reaction mixture gave a 2-BrPA yield of about 19 mol % and selectivity of about 38 mol %.