Catechol → 2,3-Dihydro-1-benzofuran-7-ol

HRID 2059008ノート

反応式

HRID 2059008 の反応式
C1(C(=CC=CC=1)O)O.[CH2:9]([O:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[OH:20])[C:10](=C)C.C(Cl)C(=C)C.C([O-])([O-])=O.[K+].[K+]>CC(C)=O>[OH:20][C:15]1[CH:16]=[CH:17][CH:18]=[C:19]2[C:14]=1[O:13][CH2:9][CH2:10]2

参加物

6

反応物 4

HCID 289CatecholHCID 112413-Chloro-2-methyl-1-propeneHCID 11430Potassium CarbonateHCID 785142-[(2-methyl-2-propenyl)oxy]phenol

生成物 1

HCID 220133742,3-Dihydro-1-benzofuran-7-ol収率 45%

試薬・触媒・溶媒 1

HCID 180Acetone溶媒

実験手順

It is furthermore known (see U.S. Pat. No. 3,474,171), that pyrocatechol can be converted into methallyloxyphenol with methallyl chloride in the presence of equivalent amounts of K2CO3 and KI in acetone as the diluent if the mixture is heated under reflux for 30 hours. The yield is 45% of theory. Rearrangement and cyclization to give 7-hydroxycoumaran are carried out at 200° to 275° C. without a solvent; no yields are given for these stages. Particular disadvantages for an industrial procedure are, in the alkylation stage, the long reaction times giving a low yield and the use of an equimolar amount of potassium iodide, which is expensive and can be recovered from the salt mixture for renewed use only with high losses. Because of the highly exothermic effect, solvent-free rearrangement of methallyloxyphenol can be carried out only with a great deal of technical effort.

後処理

  1. temperatureis heated
  2. temperatureunder reflux for 30 hours

出典と根拠

ORDレコード
ord-ce2f2453ba95400895d2adaa97cde517
出典データセット
uspto-grants-1982_03
特許番号
US04321204

反応ノート

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