合成路线:The condensation of 6-acetyl-7-hydroxy-1,2,3,4-tetrahydronaphthalene (I) with allyl bromide (A) by means of K2CO3 in DMF gives 6-acetyl-7-allyloxy-1,2,3,4-tetrahydronaphthalene (II),which is isomerized to 5-allyl-7-acetyl-6-hydroxy-1,2,3,4-tetrahydronaphthalene (III) by heating at 200 C.Hydrogenation of (III) with H2 over Pd/C in ethanol affords 5-propyl-7-acetyl-6-hydroxy-1,2,3,4-tetrahydronaphthalene (IV),which is then cyclized with diethyl oxalate (B) by means of sodium ethoxide in refluxing etha-nol to yield ethyl 10-propyl-4-oxo-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (V) [an alternative way to prepare (V) is the cyclization of (III) with diethyl oxalate (B) by means of sodium ethoxide to give ethyl 10-allyl-4-oxo-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (VI),which is then reduced to (V) with H2 over Pd/C in ethanol].The nitration of (V) with nitric acid in sulfuric acid gives ethyl 10-propyl-4-oxo-5-nitro-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (VII),which is reduced with H2 over Pd/C in ethanol-acetic acid to afford the corresponding amino derivative (VIII).Finally,this compound is diazotated with NaNO2 and H2SO4 and then treated with 50% H2SO4 at 120 C.
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参考来源:BE 0836121
合成路线:The condensation of 6-acetyl-7-hydroxy-1,2,3,4-tetrahydronaphthalene (I) with allyl bromide (A) by means of K2CO3 in DMF gives 6-acetyl-7-allyloxy-1,2,3,4-tetrahydronaphthalene (II),which is isomerized to 5-allyl-7-acetyl-6-hydroxy-1,2,3,4-tetrahydronaphthalene (III) by heating at 200 C.Hydrogenation of (III) with H2 over Pd/C in ethanol affords 5-propyl-7-acetyl-6-hydroxy-1,2,3,4-tetrahydronaphthalene (IV),which is then cyclized with diethyl oxalate (B) by means of sodium ethoxide in refluxing etha-nol to yield ethyl 10-propyl-4-oxo-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (V) [an alternative way to prepare (V) is the cyclization of (III) with diethyl oxalate (B) by means of sodium ethoxide to give ethyl 10-allyl-4-oxo-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (VI),which is then reduced to (V) with H2 over Pd/C in ethanol].The nitration of (V) with nitric acid in sulfuric acid gives ethyl 10-propyl-4-oxo-5-nitro-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2-carboxylate (VII),which is reduced with H2 over Pd/C in ethanol-acetic acid to afford the corresponding amino derivative (VIII).Finally,this compound is diazotated with NaNO2 and H2SO4 and then treated with 50% H2SO4 at 120 C.
参考文献标题:Proxicromil
文献作者:Castar,J.; Blancafort,P.; Hillier,K.; Serradell,M.N.
参考来源:Drugs Fut 1979,4(12),889
产品链接: CAS No. 60400-92-2››