p-Toluenesulfonic acid monohydrate → p-Toluenesulfonic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred slurry of 6-triphenylmethylamino-2,2-dimethyl-3-(O,O-dimethylphosphono)penam, 487 mg. (0.001 mole), in 10 ml. of dry acetone is added 190 mg. (0.001 mole) of p-toluenesulfonic acid monohydrate at 25° C. The solids dissolve slowly, giving a clear solution. After stirring at 25° C. for 15 minutes the product starts to precipitate. The stirring is continued for a further 45 minutes after the product starts to appear. The first crop is then filtered off, washed with acetone, and dried to afford the title compound as the p-toluenesulfonate salt. 1H-nmr (DMSO-d6) ppm (δ): 1.65 (s,3,CH3), 1.70 (s,3,CH3), 2.32 (s,3,CH3), 3.77 (d,J = 11,6,OCH3), 4.11 (d,J = 11, 1,C-3), 5.1 (m,l)- and 5.45 (d,J = 4,1)- C-5 and C-6 protons, 7.3 (q,4,aromatic protons). The yield is 83% of theory, M.P. 149°-151° C.

Provenance & Evidence