Tetrahedron

Photocyclization of methyl 2-arylthio-and 2-aryloxy-acetoacetates: A facile synthesis of benzoheterocycles

T Sasaki, K Hayakawa, H Ban

Index: Sasaki, Tadashi; Hayakawa, Kenji; Ban, Hiroshi Tetrahedron, 1982 , vol. 38, # 1 p. 85 - 91

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Citation Number: 6

Abstract

A series of methyl 2-arylthio-(2) and 2-aryloxy-acetoacetates (3) have been prepared and their tautomeric equilibria have been examined by 1H NMR spectroscopy. S-substitution at the α-position results in an increase of enol tautomer over 90%, while the O-analogues exist predominantly in the keto form (Table 1). Pyrex-filtered irradiation of 2-arylthio compounds 2a-1 in benzene-methanol (1: 1) solution gives benzothiophene derivatives (6a–f, 7–10) ...