Diisobutylaluminum hydride → HCID 58204562, compound

Participants

Reaction Steps

A mixture of 9-azetidin-3-yl-2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,10b-diaza-benzo[e]azulene (200 mg, 0.55 mmol), 2-bromo-2-methyl propionate (71 μL, 0.55 mmol), triethylamine (75 μL, 0.55 mmol) in DMF was heated at 55° C. for 30 h before concentrating in vacuo. The residue was partitioned between 10% MeOH in DCM and water, the aqueous extracted with 10% MeOH in DCM and the combined organic extracts dried (Na2SO4), filtered and concentrated in vacuo. The resultant residue was subjected to flash chromatography (SiO2, gradient 0 to 10% MeOH in DCM) to give 2-{3-[2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,10b-diaza-benzo[e]azulen-9-yl]-azetidin-1-yl}-2-methyl-propionic acid methyl ester 63 (56 mg, 23%). To a solution of 2-{3-[2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,10b-diaza-benzo[e]azulen-9-yl]-azetidin-1-yl}-2-methyl-propionic acid methyl ester 63 (56 mg, 0.12 mmol) in THF (1.5 mL) at −78° C. was added DIBAL (1.5 M solution in toluene, 0.24 mL, 0.36 mmol) and the mixture allowed to warm to RT over 18 h. The mixture was cooled to 0° C., further DIBAL (0.12 mL, 0.18 mmol) added dropwise and stirring continued for 45 min. The reaction was quenched by the addition of MeOH (0.5 mL) followed by Rochelle's salt saturated aqueous solution (0.5 mL), then diluted with ethyl acetate and filtered through Celite®, washing with ethyl acetate. The filtrate was concentrated in vacuo and the residue subjected to flash chromatography (SiO2, gradient 0 to 5% MeOH (+2M NH3) in DCM) to give 170 as a white solid, as illustrated in FIG. 13 (27 mg, 53%). 1H NMR (400 MHz, CDCl3): δ 7.95 (s, 1H); 7.85 (d, J=2.18 Hz, 1H); 7.23 (d, J=2.23 Hz, 1H); 7.17 (d, J=8.29 Hz, 1H); 6.87 (s, 1H); 5.74-5.66 (m, 1H); 4.55 (t, J=6.02 Hz, 2H); 3.71 (s, 3H); 3.43 (s, 2H); 3.28 (s, 2H); 3.16 (t, J=6.03 Hz, 2H); 1.59 (d, J=6.62 Hz, 6H); 1.04 (s, 6H). 1 Exchangeable proton not observed. LCMS: RT=6.43 min, M+H+=423

Provenance & Evidence