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

HRID 2059008노트

반응식

HRID 2059008 반응식
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

참가 물질

6

반응물 4

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

생성물 1

HCID 220133742,3-Dihydro-1-benzofuran-7-ol수율 45%

시약·촉매·용매 1

HCID 180Acetone용매

실험 절차

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.

후처리

  1. temperatureis heated
  2. temperatureunder reflux for 30 hours

출처 및 근거

ORD 기록
ord-ce2f2453ba95400895d2adaa97cde517
출처 데이터셋
uspto-grants-1982_03
특허 번호
US04321204

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