TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises: reacting (II) or with ester compound of formula ((Hal)-A-O-C(=O)-O-R3). ACTIVITY - Herbicide.    MECHANISM OF ACTION - None given.    ADMINISTRATION - Application of (I) is 0.1-10000 (preferably 10-3000 g) per hectare, by any suitable route.    SPECIFIC COMPOUNDS - 11 Compounds (I) are specifically claimed e.g. 1-(4-(3-(ethoxymethyl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yloxy)ethyl methyl carbonate compound of formula (Ia), methyl-3-(5-(1-(methoxycarbonyloxy)ethoxy)-1-methyl-1 H-pyrazole-4-carbonyl)-2-methyl-6-(methylsulfonyl)benzoate, 1-(4-(3-(methoxymethyl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yloxy)ethyl methyl carbonate, 1-(4-(3-(ethoxymethyl)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1 H-pyrazol-5-yloxy)ethyl ethylcarbonate and ethyl-1-(4-(3-(2-isopropoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoyl)-1-methyl-1H-pyrazol-5-yloxy)ethyl carbonate. 7 Compounds (II) are specifically claimed e.g. (5-hydroxy-1-methyl-1H-pyrazol-4-yl)(3-(2-isopropylethoxy)-2-methyl-4-(methylsulfonyl)phenyl)ketone of formula (IIa), (5-hydroxy-1,3-dimethyl-1H-pyrazol-4-yl)(3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl)ketone, (5-hydroxy-1-methyl-3-ethyl-1H-pyrazol-4-yl)(3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl)ketone, (1-ethyl-5-hydroxy-3-methyl-1H-pyrazol-4-yl)(3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl)ketone and (5-hydroxy-1-npropyl-1H-pyrazol-4-yl)(3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl)ketone.    EXAMPLE - 5-Hydroxy-1-ethylpyrazol-4-yl-3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)phenyl ketone (300 mg) was dissolved in 2-butanone (10 ml), and potassium carbonate (130 mg) and tetrabutylammonium bromide (15 mg) were added. After stirring at room temperature for 10 minutes, 1-chloroethyl methyl carbonate (purity: 85%, 270 mg) was added, followed by heating and refluxing for 3 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and poured into water and then extracted with ethyl acetate. The organic layer was washed with 1N hydrochloric acid and a saturated sodium chloride aqueous solution, followed by drying over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to afford 1-(1-ethyl-4-(3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoyl)-1H-pyrazol-5-yloxy)ethyl methyl carbonate.