(R)-camphorsulfonic acid → (Z)-3-(2-hydroxaminoethyl)-5-fluoro-2-methyl-1-(4-methylthiobenzylidene)indene
Reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)/[C:7](=[CH:11]\[C:12]1[CH:17]=[CH:16][C:15]([S:18][CH3:19])=[CH:14][CH:13]=1)/[C:6]([CH3:20])=[C:5]2[CH2:21][CH2:22][N:23](C1CCCCO1)[OH:24].[C@@]12(CS(O)(=O)=O)C(C)(C)C(CC1)CC2=O>CO>[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)/[C:7](=[CH:11]\[C:12]1[CH:17]=[CH:16][C:15]([S:18][CH3:19])=[CH:14][CH:13]=1)/[C:6]([CH3:20])=[C:5]2[CH2:21][CH2:22][NH:23][OH:24]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of the indene intermediate from Step 3 (1 g, 2.35 mmol) and (1R)-(-)-10-camphorsulfonic acid (546 mg, 2.35 mmol) in methanol (30 mL) was refluxed for 3 hours. The methanol was evaporated, the residue dissolved in ethyl acetate and the solution washed successively with water, twice with saturated aqueous sodium bicarbonate, and with water. After drying over Na2SO4, the residue obtained on evaporation of the solvent was triturated with ether and filtered to obtain the title compound as a yellow solid, mp: dec 126° C. which was identical to the product obtained in Method A, Step 4.