A non-catalytic approach to the synthesis of 5,6-dihydrobenzo[h]quinolines

作者：Pratap Ramendra; Ram Vishnu Ji^*

来源：Tetrahedron Letters, 2007, 48(15): 2755-2759.

DOI：10.1016/j.tetlet.2007.02.049

• benzo[H]quinoline
• 2-oxo-5,6-dihydro-2H-benzo[h]chromene
• ring transformation

A concise synthesis of highly functionalized 5,6-dihydrobenzo[h]quinoline-3-carbonitriles is delineated through base induced ring transformation of 4-sec-amino-2-oxo-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles with S-methylisothiourea sulfate and 1-carboxamidinepyrazole hydrochloride, separately, in DMF. Under analogous reaction conditions the ring transformation of 4-sec-amino-2-oxo-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles by formamidine acetate provided 4-sec-amino-benzo[h]quinoline-3-carbonitriles in moderate yields, while with benzamidine hydrochloride, the reaction followed the same mechanism to yield 2-phenyl-4-sec-amino-5,6-dihydrobenzo[h]quinoline-3-carbonitriles.

• 出版日期2007-4-9