TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The active carbon is high bounce ultra, CGP super (RTM: Chemically activated powdered carbon), GBG, SX plus (RTM: Acid-washed steam activated carbon), ROX 0.8 (acid washed extruded carbon) or A super euro (carbon fiber).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The reaction in step (a) occurs in the presence of a solvent comprising one or more of polar solvents comprising water or alcohols, polar aprotic solvents comprising acetonitrile, N-methylpyrrolidone, 3-6C amides, 3-6C ketones or 2-6C acetates, or non-polar solvents comprising 5-12C aromatic hydrocarbons or 2-8C ethers. The reaction mixture may be cooled prior to obtaining iloperidone. The solution may be obtained by dissolving iloperidone in one or more of organic solvent comprising a mixture of acetone and water or ethanol and water. Preferred Components: The iloperidone contains less than 0.5% (preferably less than 0.1%) of the dimer impurity (B). The salts of iloperidone are crystalline. The organic base comprises one or more of dimethyl amine, diethyl amine, dibutyl amine, triethyl amine, diisopropylethylamine, diisopropylamine, tert-butylamine, isobutylamine, pyridine, 4-dimethylaminopyridine, imidazole, N-methylmorpholine, 1,4-diazobicyclo-(2,2,2)octane, 1,8-diazabicyclo(4.3.0)non-5-ene or 1,8-diazabicyclo(5.4.0)undec-7-ene. In step (c), the base comprises sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, dimethyl diethyl amine, dibutyl amine, triethyl amine, diisopropylethylamine, diisopropylamine, tert-butylamine, isobutylamine or pyridine. The base in step (a1) and (d1) comprises organic base comprising dimethyl amine, diethyl amine, dibutyl amine, triethyl amine, diisopropylethylamine, diisopropylamine, tert-butylamine, isobutylamine, pyridine, 4-dimethylaminopyridine, imidazole, N-methylmorpholine, 1,4-diazobicyclo-(2,2,2)octane, 1,8-diazabicyclo(4.3.0)non-5-ene and 1,8-diazabicyclo(5.4.0)undec-7-ene. The base in step (b1) and (c1) comprises one or more of inorganic base comprising sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate. The organic solvent in step (c1) comprises one or more of 3-6C ketone or its mixture with water, N-methylpyrrolidone, 3-6C amides, halo-substituted 6-12C aromatic hydrocarbons, propylene glycol, dimethyl sulfoxide, dimethyl carbonate, 1-4C alcohols, a mixture 1-4C alcohol and water, acetonitrile or its mixture with water, or 2-6C acetates. The organic solvent in step (d1) comprises one or more of polar solvents comprising water, 1-4C alcohols, polar aprotic solvents comprising acetonitrile, N-methylpyrrolidone, 3-6C amides, 3-6C ketones or 2-6C acetates, non-polar solvents comprising 5-12C aromatic hydrocarbons, or 2-8C ethers. The organic solvent comprises one or more of water, methanol, ethanol, isopropanol, butanol, acetonitrile, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetone, methyl ethyl ketone, methyl isobutylketone, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, toluene, xylene, ethyl benzene, dibutyl ether, methyl tert-butyl ether, or diisopropyl ether. The solvent in step (a2) comprises one or more of 3-6C ketones comprising acetone, methyl ethyl ketone or methyl iso-butyl ketone, 3-6C amides comprising dimethylacetamide or dimethylformamide, halo-substituted 6-12C aromatic hydrocarbons comprising chlorobenzene or dichlorobenzene, 1-4C alcohols comprising methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol or 2-butanol, 2-6C acetates comprising ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, 2-8C ethers comprising dibutyl ether, methyl tert-butyl ether, diisopropyl ether or polyethylene glycol. The solvent in step (a3) comprises one or more of methylene dichloride, chlorobenzene, chloroform, tetrahydrofuran, acetone, acetonitrile, methanol or ethanol. The anti-solvent in step (a3) comprises one or more of methyl tert-butyl ether, diisopropyl ether, cyclohexane, hexane, heptane, toluene, benzene, xylene or water. The organic solvent in step (a4) comprises one or more of 1-4C alcohols comprising methanol, ethanol, isopropanol or butanol, 3-5C ketones comprising acetone, methyl ethyl ketone or methyl isobutyl ketone, acetonitrile or water. The first organic solvent comprises one or more of water, 1-4C alcohols comprising methanol, ethanol, isopropanol or n-butanol, polar aprotic solvents comprising acetonitrile, N-methylpyrrolidone, 3-6C amides comprising N,N-dimethylformamide or N,N-dimethylacetamide, 3-6C ketones comprising acetone, methylisobutyl ketone, methyl ethyl ketone, 2-6C acetates comprising ethyl acetate, isopropyl acetate, n-butyl acetate and/or isobutyl acetate. The second organic solvent comprises one or more of toluene, xylene, ethyl benzene, methylene dichloride, chlorobenzene, ethyl acetate, isopropyl acetate, n-butyl acetate, methyl tert-butyl ether, diisopropyl ether, n-hexane, n-heptane and/or cyclohexane. ACTIVITY - Neuroleptic.    MECHANISM OF ACTION - Serotonin receptor antagonist; Dopamine receptor antagonist.    EXAMPLE - A mixture of 6-flouro-3-(4-piperidinyl)-1,2-benzisoxazole (100 g), 1-(4-(3-chloropropoxy)-3-methoxyphenyl)ethanone (121.2 g) and triethylamine (55.11 g) in water (1500 ml) was heated for 15 hours at 85 degrees C. After the completion of the reaction, the reaction mixture was cooled to 25 degrees C and stirred for 30 minutes. The slurry was filtered and dried under vacuum. The wet-cake (340 g) was slurried in water (500 ml) at 25-30 degrees C for 1 hour. The product was filtered and washed with water till neutral pH. The product was dried at 50-55 degrees C to obtain iloperidone (170 g, 88%) having purity of greater than 95%.