TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: (II) is added directly to the reaction mixture obtained in step without isolating (III). (III) is isolated. The lurasidone base is converted to lurasidone oxalate. The step (c) comprises the conversion of lurasidone base to lurasidone oxalate, which is converted to lurasidone hydrochloride with hydrochloric acid, used either in gaseous form or in solution. The step (a) is performed at a temperature of 80-190 degrees C, preferably 100-140 degrees C. The step (b) is performed at a temperature of 80-190 degrees C, preferably 120-140 degrees C. Preferred Components: The solvent having a boiling point higher than 80 degrees C is toluene, xylene, 4-dioxane and/or dimethyl sulfoxide. The organic base having a pKB greater than 10 is 1,4-diazabicycloundec-7-ene (preferred), 1,5-diazabicyclo(4.3.0)non-5-ene, 1,4-diazabicyclo(2.2.2)octane, diminazen or benzamidine. The organic carboxylic acid comprises tartaric acid, pyruvic acid, maleic acid, oxalic acid or dihydroxyfumaric acid. ACTIVITY - Neuroleptic.    MECHANISM OF ACTION - None given.    EXAMPLE - 177 g of compound 4 and 150 g of compound 5 were added to a mixture consisting of dioxane (250 ml) and dimethyl sulfoxide (250 ml). The mixture was heated to a reflux temperature of 120 degrees C and 192 g of 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) was added in four portions every 20 minutes. After six hours, a further 20 g of DBU was added, and heating continued for a further 3 hours. 125 g of compound 2 and 228 g of DBU were added to the solution of compound 3, and the mixture was heated to 140 degrees C and distilled. After 8 hours heating at the temperature, the mixture was cooled to ambient temperature and diluted with 6 l of an acetone/water 1:2 mixture, and the lurasidone base was isolated by filtration (190 g). A mixture consisting of acetone (4750 ml) and lurasidone base (431 g) was refluxed until dissolved. Oxalic acid dihydrate (110 g) was added, and the mixture was cooled to ambient temperature, and then cooled for 2 hours at 10 degrees C. The solid was filtered, and 435 g of substantially pure lurasidone oxalate was obtained after drying. A mixture consisting of acetone (280 ml), water (140 ml) and lurasidone oxalate (47 g) was refluxed until dissolved. Concentrated hydrochloric acid (11 ml) was added, and the mixture was cooled at ambient temperature for 2 hours. The solid was filtered, and 36 g of lurasidone hydrochloride free of impurities exceeding 0.1% was obtained after drying.