Sulfuric Acid → HCID 131710894, compound

Participants

Reaction Steps

Trans-4-Isopropylamino-3,4-dihydro-2,2-dimethyl-6-nitro-2H-benzo[b]pyran-3-ol (3.54 g.) was added to a solution of stannous chloride (7.90 g.) in ethanol (36 ml.) and concentrated hydrochloric acid (60 ml.) and stirred for 3 hours at ambient temperature. After dilution, work-up via diethyl ether gave a gum (3.25 g.). Purification of this gum (2.00 g.) by application to silica gel plates and development with ethyl acetate/60°-80° petroleum ether mixture gave an amorphous solid (1.01 g.) which was dissolved in dilute sulphuric acid and evaporated to dryness to yield trans-4-isopropylamino-3,4-dihydro-2,2-dimethyl-6-amino-2H-benzo[b]pyran-3-ol sulphate as a light brown solid m.p. 180° - 190°.

Provenance & Evidence