Refined synthesis of 2, 3, 4, 5-tetrahydro-1, 3, 3-trimethyldipyrrin, a deceptively simple precursor to hydroporphyrins

…, J Bhaumik, HJ Kim, M Taniguchi…

Index: Ptaszek, Marcin; Bhaumik, Jayeeta; Kim, Han-Je; Taniguchi, Masahiko; Lindsey, Jonathan S. Organic Process Research and Development, 2005 , vol. 9, # 5 p. 651 - 659

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Citation Number: 39

Abstract

2, 3, 4, 5-Tetrahydro-1, 3, 3-trimethyldipyrrin (1) is a crucial building block in the rational synthesis of chlorins and oxochlorins. The prior five-step synthesis of 1 from pyrrole-2- carboxaldehyde (2) employed relatively simple and well-known reactions yet suffered from several drawbacks, including limited scale (≤ 0.5 g of 1 per run). A streamlined preparation of 1 has been developed that entails four steps:(i) nitro-aldol condensation of 2 and ...