Hydrogen Bromide → 4-Methyl-3'-nitro-6'-piperazin-1-yl-3,4,5,6-tetrahydro-2H-[1,2']bipyridinyl dihydrobromide

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Reaction Conditions

Reaction Steps

A solution of 4-(4-methyl-3′-nitro-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-6′-yl)-piperazine-1-carboxylic acid benzyl ester (as prepared in the previous step, 3.2 g, 7.3 mmol) in HOAc (50 mL) was treated with 30% HBr in HOAc (7.3 mL, 1 mL/mmol benzyl ester) and heated to 60° C. for 1 h. The reaction was cooled to room temperature and allowed to stir for 5 h, after which time Et2O was added to the reaction while stirring. The bright yellow precipitate was filtered and washed with Et2O to afford the title compound (2.6 g, 77%). 1H-NMR (CD3OD; 400 MHz): δ 8.44 (d, 1H, J=9.6 Hz), 6.95 (d, 1H, J=9.6 Hz), 4.13 (app t, 4H, J=5.2 Hz), 3.87-3.79 (m, 2H), 3.71-3.60 (m, 2H), 3.42 (app t, 4H, J=5.2 Hz), 2.09-2.00 (m, 2H), 1.99-1.88 (m, 1H), 1.69-1.55 (m, 2H), 1.09 (d, 3H, J=6.8 Hz). LC-MS (ESI, m/z): Calcd. for C15H23N5O2, 306.2 (M+H), found 306.1.

Provenance & Evidence