Dicyclohexylcarbodiimide → 4,4-Dimethyl-7-(3-methyl-2-octyl)-9-[4-(piperidino)-butyryloxy]-1,2,3,4-tetrahydrocyclopenta[c][1]benzopyran hydrochloride

関与物質

反応手順

5.0 g. (14.6 mmoles) of 4,4-dimethyl-9-hydroxy-7-(3-methyl-2-octyl)-1,2,3,4-tetrahydrocyclopenta[ c][1]benzopyran, 3.14 g. (15.2 mmoles) of dicyclohexylcarbodiimide and 3.15 g. (15.2 mmoles) of γ-piperidinobutyric acid hydrochloride (m.p. 190°-192°), Cruickshank & Sheehan J. Am. Chem. Soc. 83, 2891 (1961), were combined with 250 ml. of methylene chloride and stirred for a total of 40 hours at room temperature. The insoluble by-product of dicyclohexylurea was separated by filtration and the methylene chloride was removed using a rotary evaporator. The brown residue was treated with approximately 75 ml. of benzene, and filtered to remove a small amount of insoluble material. The benzene was evaporated and the brown, viscous residue was triturated with about 200 ml. of ether to give 4.3 g. of crude product as a light brown solid, m.p. 174°-176°C. Recrystallization from benzene gave a total of 3.5 g. (45%) of product as colorless crystals, m.p. 174°-176°C. The infrared and nuclear magnetic resonance spectra were in agreement with the proposed structure.

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