Formaldehyde → HCID 59504625, compound

Participants

Reaction Steps

A mixture of 3-(4-{5-[5-methyl-1-(4-methylbenzyl)-1H-pyrazol-3-yl]-1,2,4-oxadiazol-3-yl}-phenyl)imidazolidin-4-one (Example 141, 50 mg, 0.12 mmol) and aqueous formaldehyde solution (37%, 0.09 mL, 1.21 mmol) in acetic acid (0.5 mL) was stirred at rt for 15 min and then cooled to 0° C. Sodium triacetoxyborohydride (384 mg, 1.81 mmol) was added, and the mixture was stirred for 1 h at 0° C. and then at rt over night. Dichloromethane was added, and the mixture was extracted twice with saturated aqueous sodium bicarbonate solution, whereupon it was dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to preparative HPLC (RP-18 column; acetonitrile/water gradient containing 0.1% trifluoroacetic acid). The product-containing fractions were combined, and the solvent was partly removed which resulted in precipitation of a solid. A neutral pH was established by adding saturated aqueous sodium bicarbonate solution, and the mixture was stirred for 30 min whereupon the solid was filtered off and dried under reduced pressure to yield the title compound (30 mg, 59%): 1H NMR (400 MHz, CDCl3) δ 8.22 (d, 2H), 7.69 (d, 2H), 7.12 (d, 2H), 7.08 (d, 2H), 6.80 (s, 1H), 5.41 (s, 2H), 4.61 (s, 2H), 3.48 (s, 2H), 2.58 (s, 3H), 2.33 (s, 3H), 2.27 (s, 3H); ES-MS m/z 429 (MH)+, HPLC RT (Method D) 2.31 min.

Provenance & Evidence