2-Aminophenol → 2-(2H-Pyrrol-2-ylidene)-2,3-dihydro-1,3-benzoxazole

HRID 6429

反応式

HRID 6429 の反応式
[NH:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([OH:8])=O.[NH2:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=1O.B(O)(O)O>C1(C)C(C)=CC=CC=1.C(OCC)(=O)C>[NH:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]1[O:8][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=2[N:9]=1

参加物

6

反応物 3

HCID 58012-AminophenolHCID 7628Boric AcidHCID 12473Pyrrole-2-Carboxylic Acid

生成物 1

HCID 1356254822-(2H-Pyrrol-2-ylidene)-2,3-dihydro-1,3-benzoxazole収率 52%

試薬・触媒・溶媒 2

HCID 7237O-Xylene溶媒HCID 8857Ethyl Acetate溶媒

実験手順

2-(Pyrrol-2-yl)benzoxazole was prepared as follows: A mixture of 5.55 g (0.05 mol) of pyrrole-2-carboxylic acid and 5.46 g (0.05 mol) of o-aminophenol and 3.09 g (0.05 mol) boric acid in 50 mL of xylene was heated under reflux for 3 days while removing water which was generated from reaction using a Dean-Stark trap. The cooled reaction mixture was diluted with 100 mL of ethyl acetate, washed with 150 mL of 5% sodium hydroxide solution and then with 150 mL of water. The separated organic layer was dried over anhydrous sodium sulfate. The resulting crude product was purified by column chromatography on silica gel with 20% hexane in chloroform as eluant. The desired product, 2-(pyrrol-2-yl)benzoxazole (4.75 g, 52%), was obtained as a white solid. m.p. 149°-150° C.; 1H NMR (CDCl3) δ6.38-6.40 (m, 1H, ArH), 7.05-7.06 (m, 1H, ArH), 7.11-7.13 (m, 1H, ArH), 7.29-7.36 (m, 2H, 2xArH), 7.53-7.56 (m, 1H, ArH), 7.65-7.69 (m, 1H, ArH), 10.9 (bs, 1H, NH).

後処理

  1. custom2-(Pyrrol-2-yl)benzoxazole was prepared
  2. temperaturewas heated
  3. temperatureunder reflux for 3 days
  4. customwhile removing water which
  5. customwas generated from reaction
  6. customThe cooled reaction mixture
  7. washwashed with 150 mL of 5% sodium hydroxide solution
  8. dry with materialThe separated organic layer was dried over anhydrous sodium sulfate
  9. customThe resulting crude product was purified by column chromatography on silica gel with 20% hexane in chloroform as eluant

出典と根拠

ORDレコード
ord-2288569fc3ee4fffb9e3876b2052db84
出典データセット
uspto-grants-1993_09
特許番号
US05248782

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