Hydrochloric Acid → 2-(4-Aminobenzyl)-5-methyl-1,2,5-thiadiazolidine-1,1-dioxide. Hydrochloride

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Reaction Steps

A suspension of the product from Step 1 (20 g, 74.72 mmol) in a mixture of absolute ethanol (300 ml), ethyl acetate (150 ml), 2N hydrochloric acid (39 ml) and water (25 ml), was hydrogenated at 30 psi for 7 minutes over 10% palladium on carbon (2 g). The catalyst was removed by filtration, washed with ethanol (2×30 ml) and solvents were removed under vacuum. The remaining residue was azeotropically dried with absolute ethanol (1×150 ml) and further dried at high vacuum to give 20.36 g (99.5%) of the required title compound as a white solid. A sample recrystallised from absolute ethanol showed: mp 153°-156° C. (white needles); δH (250 MHz, DMSO-d6) 7.42 (2H, d, J=8.4 Hz, Ar--H), 7.29 (2H, d, J=8.4 Hz, Ar--H), 4.15 (2H, s, Ar--CH2 --N), 3.27--3.17 (4H, m, N--CH2CH2 --N), 2.62 (3H, s, --NMe); m/z (CI) 240 (M+ -1).

Provenance & Evidence