Hydrochloric Acid → Ethyl 3-Hydrazino-4-(trifluoromethyl)benzoate hydrochloride

HRID 257577ノート

反応式

HRID 257577 の反応式
[NH2:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1[C:13]([F:16])([F:15])[F:14])[C:5]([O:7][CH2:8][CH3:9])=[O:6].[N:17]([O-])=O.[Na+].[ClH:21]>O>[ClH:21].[NH:1]([C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1[C:13]([F:14])([F:15])[F:16])[C:5]([O:7][CH2:8][CH3:9])=[O:6])[NH2:17]

参加物

5

反応物 3

HCID 313Hydrochloric Acid2 回HCID 19783159Ethyl 3-amino-4-(trifluoromethyl)benzoateHCID 23668193Sodium Nitrite

生成物 1

HCID 19783209Ethyl 3-Hydrazino-4-(trifluoromethyl)benzoate hydrochloride

試薬・触媒・溶媒 1

HCID 962Water溶媒

実験手順

A mixture of 500 mg (2.15 mmol) of ethyl 3-amino-4-(trifluoromethyl)benzoate (from Step D) and 5 mL of concentrated hydrochloric acid was stirred at 0°-5° C. as a cold solution of 173 mg (2.50 mmol) of sodium nitrite in 0.8 mL of H2O was added. After being stirred at 0°-5° C. for 1 hour, the mixture was filtered while cold, and the filtrate was poured into a solution of 1.02 g (4.5 mmol) of stannous chloride dihydrate in 2 mL of concentrated hydrochloric acid stirred at 0° C. Precipitation occurred immediately. The mixture was kept in an ice bath for 1.5 hours, and then the solid was collected by filtration. The solid is dried to yield the title compound suitable for use in the pyrazole ring formation reaction. In this experiment, the material was characterized as the free base by partitioning the solid hydrochloride between 2N Na2CO3 (aqueous) and ethyl acetate. The ethyl acetate phase was washed with brine, dried, filtered, and concentrated to yield 375 mg (70%) of the free base of the title compound as a pale yellow oil; homogeneous by TLC in 4:1 hexane-EtOAc and 98:2 CH2Cl2 --MeOH. 200 MHz 1H NMR (CD3OD) for free base: δ1.38 (t, J=7.1 Hz, 3H), 4.36 (q, J=7.1 Hz, 2H), 7.34 (d, J=8 Hz, 1H), 7.48 (d, J= 8 Hz, 1H), 8.05 (s, 1H).

後処理

  1. additionwas added
  2. filtrationthe mixture was filtered while cold, and the filtrate
  3. stirringstirred at 0° C
  4. customPrecipitation
  5. waitThe mixture was kept in an ice bath for 1.5 hours
  6. filtrationthe solid was collected by filtration
  7. customThe solid is dried

出典と根拠

ORDレコード
ord-0f45e88873654ece9aa9a2413c9dfb00
出典データセット
uspto-grants-1993_11
特許番号
US05262412

反応ノート

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