Tetraethyl orthocarbonate → 5-Biphenyl-4-yl-2-ethoxy-6,6-dimethyl-5,6-dihydro-1,4,3-oxathiazine 4,4-dioxide

Participants

Reaction Conditions

Reaction Steps

A mixture of 3.14 g of 1-biphenyl-4-yl-2-hydroxy-2-methylpropane-1-sulfonamide in 75 ml of tetraethoxymethane and 15 ml of acetic acid was stirred at 100° C. for 24 hours. The conversion was checked by LCMS. Since it was incomplete, the reaction mixture was admixed with a further 15 ml of acetic acid and stirred at 120° C. for 4 hours. Subsequently, a further 20 ml of tetraethoxymethane were added and the reaction mixture was stirred at 120° C. for 5 hours. Since, by checking with LCMS, no further conversion had been achieved, the solvent was removed under reduced pressure and the residue was purified by means of normal phase chromatography using a Flashmaster with an n-heptane/ethyl acetate gradient. The product-containing fractions were combined and concentrated by rotary evaporation. This gave the product (1.04 g) with a molecular weight of 359.5 g/mol (C19H21NO4S).

Provenance & Evidence