تفاعل #2028873
ord-be6a99d64d3143e1bb8b649e372cc67c
معادلة التفاعل
المتفاعلات
الكواشف
المذيبات
ظروف التفاعل
المعالجة
- 1أخرىThe crude reaction
- 2غسيلwashed with potassium bisulfate (0.1N solution), brine
- 3تجفيفdried over MgSO4
- 4ترشيحfiltered
- 5تركيزconcentrated in vacuo
الإجراء التجريبي
To a stirred solution of 3,5-fluoro-4-methoxyacetophenone from Step 1 (6.46 g, 34.70 mmol) and dimethyl oxalate (6.15 g, 52.05 mmol) in methanol (80 mL), was added sodium methoxide solution (13.4 mL of 25% solution, 58.99 mmol) in one portion and the reaction stirred overnight. The crude reaction was diluted with methylene chloride, washed with potassium bisulfate (0.1N solution), brine, dried over MgSO4, filtered, and concentrated in vacuo yielding methyl 4-(3,5-difluoro-4-methoxyphenyl)-2,4-dioxo-butanoate as an off white crystalline solid which was used as is. A mixture of 4-(3,5-difluoro-4-methoxyphenyl)-2,4-dioxo-butanoate and 4-sulfonamidophenylhydrazine hydrochloride salt (7.76 g, 34.70 mmol) dissolved in methanol was warmed to reflux for 9 hours. Upon allowing the clear reaction to cool to room temperature, a crystalline precipitate formed which was collected by vacuum filtration yielding 5.45 g, (37% based upon the 3,5-difluoro-4-methoxyacetophenone) of methyl 1-(4-aminosulfonylphenyl)-5-(3,5-difluoro-4-methoxyphenyl)-1-H-pyrazole-3-carboxylate as an off-white solid: mp 185°-190° C.; 1H NMR (CDCl3/300 mHz) 7.95 (d, J=8.86, 2H), 7.49 (d, J=8.86, 2H), 7.02 (s, 1H), 6.77 (m, 2H), 4.99 (s, 2H, 4.04 (s, 3H), 3.98 (s, 3H); 19F NMR (CDCl3/300 mHz) −126.66. Anal. Calc'd for C17H13F2N3O3S: C, 51.06; H, 3.57; N, 9.92. Found: C, 51.06; H, 3.54, N, 9.99.