Hydrazine → HCID 20663658, compound

Participants

Reaction Steps

A mixture of 1 (360 mg, 2.0 mmol) and 3-(4-chlorobenzyl)-2-hydrazino-3,5-dihydroimidazol-4-one (compound 16, commercially available from Maybridge Chemical Co., Ltd., Ryan Scientific #RF03409; 500 mg, 2.1 mmol) in 6 mL of absolute ethanol was treated with 1 drop of AcOH and was warmed on a steam bath until homogeneous. The mixture was allowed to stand at 23 ° C. overnight, whereupon the 137 mg of the starting hydrazine that had separated as crystals (mp 186-188° C.) was removed by suction filtration. The filtrate was rotary evaporated to dryness, and the residue was triturated with Et2O to give 528 mg (69%, 91% based on unrecovered hydrazine) of the methoxy precursor (compound 17) as a pale yellow powder: mp 135-145° C. (EtOH). 1H NMR ((CD3)2SO) δ 9.16 (s, exchanges with D2O, 1, OH), 7.62 (d, J=8.4 Hz, 1), 7.40 (d, J =8.5 Hz, 2, p-CICA), 7.32 (d, J=8.5 Hz, 2, p-ClC6H4), 7.12 (m, 3), 6.97 (d, J=8.0 Hz, 1), 6.85 (d, J =8.0 Hz, 1), 6.68 (s, 1), 4.23 (d, J=5.6 Hz, 2, benzyl-CH2), 3.67 (s, 3, OCH3). Low-resolution DCI mass spectrum, m/z 383 (2%, MH+). Deprotection of 17 can be effected using conventional techniques to form 18.

Provenance & Evidence