Dibutylamine → HCID 18369518, compound

Participants

Reaction Steps

To a 0° solution of oxalyl chloride (479 mL, 5.49 mmol) in THF (10 mL) under nitrogen was added DIPEA (2.28 mL, 13.07 mmol) and dibutylamine (925 mL, 5.49 mmol). The resulting mixture was stirred at 0° for 5 min, whereby (dibutylamino)oxoacetyl chloride is formed, then transferred via syringe to a solution of 4-(4-aminophenyl)-2-aminothiazole (corresponding to the deprotected title compound of either Example 1(a) or 1(b)). The resulting mixture was stirred under nitrogen for 4 h, after which time another batch of freshly prepared (N,N-dibutylamino)oxalylchloride (prepared in the same manner and with the same amounts as above) was added to the reaction mixture. The stirring was continued for 1 h. The mixture was then diluted with EtOAc and extracted with 10% aqueous HCl. This aqueous extract was washed with EtOAc:Hex (1:1), then filtered. The collected solid, containing the desired product as its hydrochloride salt, was treated with 2N aqueous NaOH and extracted with EtOAc. This latter extract was washed with H2O, dried (MgSO4) and concentrated under reduced pressure to give a solid (398 mg) which was further purified by crystallization from EtOAc/MeOH to give the title compound (240 mg, 12% yield) as a beige solid: M.p. 178-179° C.; 1H NMR (400 MHz, DMSO-d6) δ10.68 (s, 1H), 7.75 (d, 2H, J=8.7 Hz), 7.64 (d, 2H, J=9.0 Hz), 7.02 (s, 2H), 6.92 (s, 1H), 3.33 (m, 4H), 1.50-1.60 (m, 4H), 1.33 (sixt., 4H, J=7.5 Hz), 1.25 (sixt., 4H, J=7.5 Hz), 0.92 (t, 3H, J=7.5 Hz), 0.82 (t, 3H, J=7.5 Hz); MS (FAB) m/z 375 (MH)+. Anal. Calcd for C19H26N4O2S: C, 60.94; H, 7.00; N, 14.96. Found: C, 60.82; H, 6.85; N, 14.95.

Provenance & Evidence