Hydrazine hydrate (1:1) → N~2~,N~2~,N~7~,N~7~-Tetraethyl-9-hydrazinylidene-9H-fluorene-2,7-diamine

Participants

Reaction Steps

2,7-Bis(diethylamino)-9-fluorenone (11.5 g, 35.66 mmol), 50 ml of 2-propanol, 98% hydrazine monohydrate (5.2 ml, 0.11 mol, from Aldrich), and 8 drops of concentrated hydrochloric acid (obtained from Aldrich) were added to a 100 ml 3-neck round bottom flask equipped with a reflux condenser and a mechanical stirrer. The mixture was refluxed with an intensive stirring until 2,7-bis(diethylamino)-9-fluorenone disappeared (1.5 hours). The reaction mixture was cooled to room temperature to form crystals. The crystals were filtered off, washed first with water, and then with a mixture of 2-propanol and n-hexane to yield 9.5 g (79%) of the hydrazone. The melting point was found to be 150–151° C. (recrystallized from 2-propanol). The 1H NMR spectrum (100 MHz) of the product in CDCl3 was characterized by the following chemical shifts (δ, ppm): 7.50–7.20 (m, 4H, Ar); 6.82–6.50 (m, 2H, Ar); 7.10 (s, br, 2H, NH2); 7.00 (q, 8H, N(CH2CH3)2); and 3.75 (t, J=7.1 Hz, 12H, N(CH2CH3)2). An elemental analysis yielded the following results in weight percent: C, 74.69; H, 8.28; N, 16.52, which compared with the following calculated values for C21H28N4 in weight percent: C, 74.96; H, 8.39; N, 16.65.

Provenance & Evidence