p-Toluenesulfonic acid → p-Toluenesulfonic acid

Participants

Reaction Steps

To a solution of (S)-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxylic acid, p-toluenesulfonate (6.0 g.) in 30 ml. of anhydrous dimethylformamide at 50 ° under argon is added a dimethylformamide solution of diphenyldiazomethane (3.6) portionwise. After 10 minutes at 50°, the solvent is removed under reduced pressure. The residue is dissolved in ethyl acetate and precipitated with ether. The solvent is then decanted and the residue triturated with ethyl acetate/ether to give (S)-1,4-dithia-7-azaspiro [4.4]nonane-8-carboxylic acid, diphenylmethyl ester, p-toluenesulfonate.

Provenance & Evidence