반응식
NC1C2OC(C(OCC)=O)(C)CC=2C=CC=1.ClC1C=CC(O)=C(C=1)C=O.ClC(C)C(OCC)=O.[Cl:35][C:36]1[CH:37]=[CH:38][C:39]2[O:43][C:42]([C:45]([O:47][CH2:48][CH3:49])=[O:46])([CH3:44])[CH:41](O)[C:40]=2[CH:51]=1.O1C2C=CC=CC=2C=C1.S(Cl)(Cl)=O.[H][H]>CN(C)C=O.C(Cl)Cl.[Pd].C(O)C.N1C=CC=CC=1>[Cl:35][C:36]1[CH:37]=[CH:38][C:39]2[O:43][C:42]([C:45]([O:47][CH2:48][CH3:49])=[O:46])([CH3:44])[CH2:41][C:40]=2[CH:51]=1참가 물질
반응물 7
생성물 1
시약·촉매·용매 5
실험 절차
Schema 7 illustrates the synthesis of an amino substituted 2,3-dihydro-2-alkoxycarbonyl-2-alkylbenzofuran, for example, 7-amino-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran by the cyclization of 5-chloro-2-hydroxybenzaldehyde with an alkyl 2-chloropropionate, for example, ethyl 2-chloropropionate, under basic conditions in N,N-dimethylformamide at 60°-70° C., affording the corresponding 5-chloro-2-ethoxycarbonyl-2,3-dihydro-3-hydroxy-2-methylbenzofuran (XXVII). The so-prepared benzofuran is chlorinated with thionyl chloride in the presence of pyridine in methylene chloride at 0°-10° C., then dechlorinated by treatment with hydrogen in the presence of 10% palladium on carbon in ethanol, yielding the corresponding 3-unsubstituted intermediate 5-chloro-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran (XXX). The 3-unsubstituted benzofuran is in turn nitrated with 90% nitric acid and concentrated sulfuric acid at 10°-16° C., affording 5-chloro-2-ethoxycarbonyl-2,3-dihydro-2-methyl-7-nitrobenzofuran (XXXI), which is then hydrogenated in the presence of 10% palladium on carbon in ethanol, affording the free amine intermediate 7-amino-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran ((XXXII). The so-prepared intermediate is optionally halogenated with, for example, N-bromosuccinimide in N,N-dimethylformamide, affording the corresponding 7-amino-4-bromo-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran (XXXIII) intermediate.
후처리
- customat 60°-70° C.
출처 및 근거
- ORD 기록
- ord-c6f70a368c484460b53c81eeb530203a
- 출처 데이터셋
- uspto-grants-1996_05
- 특허 번호
- US05521147
연결된 노트
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