- Studies in Antifertility Agents: Part XXIX - synthesis of 4--3-benzylchromans
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7-H/Methoxy-4-chromanones (1, 2), obtained by PPA cyclization of the respective β-aryloxypropionic acids, on treatment with araldehydes (3, 4) give the corresponding 3-arylidene-4-chromanones (5, 6).Catalytic hydrogenation of 5 and 6 over Pd-C (10percent) with one mole of hydrogen affords 3-benzyl-4-chromanones (7, 8), while hydrogenation of 6 yields 3-benzyl-7-methoxychroman (9).NaBH4 reduction of 7 and 8 gives the corresponding 4-chromanols (10, 11) as a mixture of 3,4-cis- and -trans-isomers, which are arylated as such with PhOH-AlCl3 to give 4-(p-hydroxyphenyl)chromans(12, 13) as the main products.Treatment of 12 and 13 with Ac2O-pyridine and with p-NO2C6H4COCl-pyridine yields the corresponding p-acetoxy (14, 15) and p-nitrobenzoyloxy (16, 17) derivatives.Alkylation of 12 and 13 with N-(β-chloroethyl)pyrrolidine hydrochloride furnishes the title compounds, 4--3-(p-chloro/H)benzyl-7-H/methoxy-chromans (18, 19).None of these compounds prevents pregnancy at 5 mg/kg dose in rats.
- Sangwan, Naresh K.,Rastogi, Shri Nivas
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p. 500 - 503
(2007/10/02)
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