2-hydroxy-N,N-dimethylbenzenesulfonamide

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

Procedure: 2.24 ml (47.4 mmol, 1.3 eq) of fuming nitric acid at 90% were added, over the course of 15 minutes, to a mixture of 7.17 g (35.6 mmol, 1 eq) of 2-hydroxy-N,N-dimethylbenzenesulfonamide in 35.5 ml of acetic acid in a bath at 5° C. The reaction medium was then stirred at ambient temperature. After one and a half hours, the reaction medium was hydrolyzed with water and brine. The reaction medium was then extracted with a 4/1 ethyl acetate/heptane mixture (2×100 ml). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The solid obtained (8.66 g) was combined with GUL1537-178 and was chromatographed on silica gel (prepacked column, eluent heptane/(ethyl acetate+1% methanol), from 20% to 65% of (ethyl acetate+1% methanol)). A fraction enriched in ortho isomer was isolated, that is to say 3.7 g of a yellow solid. This solid was recrystallized from 40 ml of ethanol. 1.93 g of product were obtained in the form of a pale yellow solid. Yield=20%. After one and a half hours The reaction medium was then extracted with a 4/1 ethyl acetate/heptane mixture (2×100 ml) dried over anhydrous sodium sulfate filtered concentrated The solid obtained (8.66 g) was chromatographed on silica gel (prepacked column, eluent heptane/(ethyl acetate+1% methanol), from 20% to 65% of (ethyl acetate+1% methanol)) was isolated This solid was recrystallized from 40 ml of ethanol

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 200 ml (200 mmol, 4.9 eq) of a 1 M solution of tribromoborane in dichloromethane were added dropwise to a solution of 8.78 g (40.8 mmol, 1 eq) of 2-methoxy-N,N-dimethylbenzenesulfonamide in 250 ml of dichloromethane at −70° C. under nitrogen. The reaction medium was left at −70° C. for one hour and was then left to return to 10° C. for one and a half hours. The reaction medium was then cooled to −70° C. and approximately 100 ml of methanol were added dropwise (approximately one hour of addition). The reaction medium was then left to return to ambient temperature and was concentrated. The residue obtained was filtered off on silica with the eluent 6/4 heptane/ethyl acetate. 7.81 g of product were obtained in the form of a beige solid. Yield=95%. was then left to return to 10° C. for one and a half hours (approximately one hour of addition) The reaction medium was then left to return to ambient temperature was concentrated The residue obtained was filtered off on silica with the eluent 6/4 heptane/ethyl acetate