合成路线1

Alkylation of the spiro lactone (VI) with dibromide (VII) in the presence of lithium hexamethyldisilazide gives rise to the tricyclic spiro compound (VIII). After acidic Boc group cleavage in (VIII), the resultant secondary amine (IX) is reductively alkylated with aldehyde (V) to produce (X) as a diastereomeric mixture. Partial reduction of lactone (X) with DIBAL provides lactol (XI), which is further converted to nitrile (XII) upon treatment with cyanotrimethylsilane and boron trifluoride. Acidic hydrolysis of nitrile (XII), followed by esterification of the resultant carboxylic acid (XIII) furnishes the methyl ester (XIV)

合成路线2

合成路线3

Friedel–Crafts acylation of 2-tert-butylphenol (I) with acetyl chloride (II) in the presence of AlCl3 in cold toluene gives 1-(3-tert-butyl-4-hydroxyphenyl)ethanone (III) (1, 2), which by nitration with HNO3 in cold H2O/CH2Cl2 provides 1-(3-tert-butyl-4-hydroxy-5-nitrophenyl)ethanone (IV). O-Alkylation of phenol (IV) with methyl iodide by means of K2CO3 in DMF produces the methyl ether (V), which is reduced at the nitro group with Fe and NH4Cl in EtOH/H2O to afford the corresponding amine (VI). Cyclocondensation of the aniline derivative (VI) with bis(2-bromoethyl) ether (VII) by means of NaI and K2CO3 in DMF provides the 3-morpholino-acetophenone derivative (VIII). α-Halogenation of acetophenone (VIII) with NBS by means of Et3N and TBDMSOTf in THF yields the corresponding bromoacetophenone (IX) , which is finally condensed with isoindole derivative (X) in THF or DMF .
The isoindole intermediate (X) is prepared by dialkylation of 3-fluorocatechol (XI) with ethyl iodide (XII) in the presence of K2CO3 in DMF to give 1,2-diethoxy-3-fluorobenzene (XIII), which is brominated with Br2 by means of NaOAc in AcOH at 70 °C to yield 1,2-dibromo-4,5-diethoxy-3-fluorobenzene (XIV). Bromide substitution in intermediate (XIV) with CuCN in DMF at 150 °C affords 4,5-diethoxy-3-fluorophthalonitrile (XV), which is finally submitted to reductive cyclization with H2 over PtO2 in EtOAc/EtOH/MeOH .