Toluene → Methyl 6-hydroxy-3-phenyl-3-(4-pyrrolidinophenyl)-2H-naphtho[1,2-b]pyran-5-carboxylate

Reaction equation

[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([OH:12])=[CH:4][C:3]=1[C:13]([O:15][CH3:16])=[O:14].[C:17]1([C:23]([C:27]2[CH:32]=[CH:31][C:30]([N:33]3[CH2:37][CH2:36][CH2:35][CH2:34]3)=[CH:29][CH:28]=2)(O)[C:24]#C)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.[C:38]1(C)C=CC=CC=1>>[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH:5]2[O:12][CH2:38][C:23]([C:17]3[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=3)([C:27]3[CH:32]=[CH:31][C:30]([N:33]4[CH2:34][CH2:35][CH2:36][CH2:37]4)=[CH:29][CH:28]=3)[CH:24]=[C:4]2[C:3]=1[C:13]([O:15][CH3:16])=[O:14]

Participants

Reactant 3

HCID 1140Toluene

HCID 604167Methyl 1,4-dihydroxy-2-naphthoate

HCID 224637731-Phenyl-1-(4-pyrrolidinophenyl)prop-2-yn-1-ol

Product 1

HCID 67162696Methyl 6-hydroxy-3-phenyl-3-(4-pyrrolidinophenyl)-2H-naphtho[1,2-b]pyran-5-carboxylateYield 62%

Procedure

A mixture of methyl 1,4-dihydroxynaphthalene-2-carboxylate (3.93 g, 18 mmol), 1-phenyl-1-(4-pyrrolidinophenyl)prop-2-yn-1-ol (5 g, 18 mmol) and Al2O3 (4 g) in PhMe (100 mL) was heated at reflux for 1.5 h, cooled, filtered, the residue washed with DCM and the solvent removed under reduced pressure. The residue was filtered through a short plug of silica using DCM (40% in hexanes) as eluent. The solvent was removed under reduced pressure and the residue was crystallized from Et2O-hexanes to give the title compound (5.47 g, 62%) as a yellow powder.