SYNTHESIS OF ISOQUINOLINES .3. A NEW SYNTHESIS OF 1,2,3,4-TETRAHYDROISOQUINOLINES
SYNTHESIS OF ISOQUINOLINES .3. A NEW SYNTHESIS OF 1,2,3,4-TETRAHYDROISOQUINOLINES
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DOI：
10.1021/jo01018a030
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发表时间：
1965-01-01
影响因子：
3.6
通讯作者：
EBERMANN, R
中科院分区：
文献类型：
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作者：
BOBBITT, JM;KIELY, JMN;EBERMANN, R
本研究的最初目的是合成7-羟基-6-甲氧基异喹啉(5)，用于异喹啉生物碱合成程序。在工作过程中，5被生产出来，但更重要的是，发现了一种新的1,2,3,4 -四氢异喹啉化合物的合成方法。新合成具有收率高、实验简单等特点。获得5的最有吸引力的途径是由异香兰素合成Pomeranz-Fritsch3-5。据此，制备了1，并在多种条件下用硫酸进行了处理。焦油是唯一的产物。Pomeranz-Fritsch合成最常见的变化（Fischer变化5·6）涉及用发烟硫酸处理n -苄基乙醛二乙基缩醛(2)。1 - 2的催化还原效果良好，用酸处理2得到5，产率为12%。化合物5是结晶的，表征为苦味酸酯和苯乙烯酸酯。其结构通过甲基化被证实为已知的化合物6.7
The initial goal of this research was to synthesize 7-hydroxy-6-methoxyisoquinoline (5) for use in a program of isoquinoline alkaloid synthesis. During the course of the work, 5 was produced, but, more importantly, a new synthesis of 1, 2, 3, 4-tetrahydroisoquinolines was discovered. The new synthesis is characterized by high yields and experimental simplicity.The most attractive route to 5 involved a Pomeranz-Fritsch3-5 synthesis from iso vanillin. Accordingly, 1 was prepared and treated with sulfuric acid under a variety ofconditions. Tars were the only products. The most common variation of the Pomeranz-Fritsch synthesis (the Fischer variation5· 6) would involve treatment of the N-benzylaminoacetaldehyde diethyl acetal (2) with fuming sulfuric acid. Catalytic re-duction of 1 to 2 proceeded satisfactorily and treatment of 2 with acid yielded 5 in 12% yield. Compound 5 was crystalline and was characterized as a picrate and a styphnate. Its structure was confirmed by methylation to the known compound 6.7