Trifluoroacetic acid → 5-Ethyl-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide

HRID 544801ノート

反応式

HRID 544801 の反応式
C(OC([NH:8][NH:9][C:10]([C:12]1[CH:21]=[CH:20][C:15]2[O:16][CH2:17][CH2:18][O:19][C:14]=2[C:13]=1[CH2:22][CH3:23])=[O:11])=O)(C)(C)C.FC(F)(F)C(O)=O.[OH-].[Na+].O>O>[CH2:22]([C:13]1[C:14]2[O:19][CH2:18][CH2:17][O:16][C:15]=2[CH:20]=[CH:21][C:12]=1[C:10]([NH:9][NH2:8])=[O:11])[CH3:23]

参加物

5

反応物 3

HCID 6422Trifluoroacetic acidHCID 23719242Sodium hydroxide--water (1/1/1)HCID 59838592N'-(5-ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carbonyl)-hydrazinecarboxylic acid tert-butyl ester

生成物 1

HCID 450954525-Ethyl-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide収率 129.9%

試薬・触媒・溶媒 1

HCID 962Water溶媒

実験手順

5.15 g (16 mmol) of N′-(5-ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carbonyl)-hydrazinecarboxylic acid tert-butyl ester were added to a 200 mL round bottom flask. About 20 mL of trifluoroacetic acid were added and the reaction mixture was stirred at room temperature for 24 hours. Then about 40 mL of water were added, followed by the slow addition of cold 10% NaOH/H2O, with stirring, until the acid was neutralized (pH˜14). The reaction mixture was transferred to a separatory funnel and extracted with ethyl acetate by shaking gently (caution: gas evolution). The ethyl acetate extract was dried and evaporated to yield 5.51 g of a pale, viscous yellow semi-solid. The material was then placed in a 50° C. vacuum oven for about 1 hour to yield 4.62 g of 5-ethyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid hydrazide. The t-Boc cleavage is best accomplished with neat trifluoroacetic acid; use of adjunctive solvents always resulted in much lower yields. 1H NMR (CDCl3, 500 MHz) δ (ppm): 7.0 (br, 1H), 6.83 (m, 1H), 6.71 (m, 1H), 4.28 (br s, 4H), 2.76 (m, 2H), 1.6 (br, 2H), 1.17 (t, 3H).

後処理

  1. stirringwith stirring, until the acid
  2. customThe reaction mixture was transferred to a separatory funnel
  3. extractionextracted with ethyl acetate
  4. stirringby shaking gently (caution: gas evolution)
  5. extractionThe ethyl acetate extract
  6. customwas dried
  7. customevaporated
  8. customto yield 5.51 g of a pale, viscous yellow semi-solid
  9. customwas then placed in a 50° C.
  10. customfor about 1 hour

出典と根拠

ORDレコード
ord-01f860ad58f2446fbb62846450c3870e
出典データセット
uspto-grants-2011_05
特許番号
US07935510B2

反応ノート

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