2,4-Dichlorobenzaldehyde → HCID 136348430, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-1,3-dimethyl-pyrazol (1.87 g, 16.8 mmol), 2,4-dichlorobenzaldehyde (2.95 g, 16.8 mmol, Fluorochem), and 2-mercapto-2-methylpropanoic acid (2.5 g, 20.8 mmol) was heated, in a microwave for about 60 min, at about 100° C. Subsequently, the reaction mixture was sealed and heated, for about 24 h, at about 150° C. After cooling to rt, THF (300 ml) was added, followed by EDC.HCl (4.25 g, 22 mmol) and DMAP (4-dimethylamino-pyridine, 0.2 g, 1.64 mmol). Subsequently, the reaction mixture was stirred for about 24 h, at rt. NaOH (2 M aqueous, 10 mL) and ethyl acetate (200 mL) were added. The layers were separated and the aqueous layer was extracted with ethyl acetate (50 mL). The combined organic layers were washed with water (2×50 mL), dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by column chromatography (SiO2, diethyl ether, followed by ethyl acetate) to afford 4-(2,4-dichlorophenyl)-1,3,6,6-tetramethyl-4,8-dihydropyrazolo[3,4-e][1,4]thiazepin-7-one (3.11 g, 8.4 mmol, 50%) as white solid: 1H-NMR (CDCl3, Bruker 400 MHz) δ 1.51 (3 H, s); 1.64 (3 H, s); 1.67 (3H, s); 3.78 (3H, s); 5.77 (1H, s); 7.17 (1H, dd, J=8.4, 2.0 Hz); 7.28 (1 H, d, J=8.4 Hz); 7.41 (1 H, d, J=2.0 Hz); H, m); 8.43 (1 H, bs).

Provenance & Evidence