Acetic Acid → Hydrochloric Acid

Participants

Reaction Steps

Following the procedure of Example 2, 6-chloro-4-cyano-4-trimethylsilyloxy-3,4-dihydro-2H-1-benzopyran (6.0 g.) and stannous chloride dihydrate (30 g.) were reacted in glacial acetic acid (25 ml.) and concentrated hydrochloric acid (25 ml.) to form 6-chloro-3,4-dihydro-2H-1-benzopyran-4-carboxylic acid. Filtration and chromatography over silica gel (300 ml.) eluted with chloroform:hexane (1:1) yielded 2.91 g. of product, m.p. 90°-90.5° C. (sublimed).

Provenance & Evidence