TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The base (B1) is sodium hydride, potassium hydride, lithium or calcium hydride. The catalyst is sodium tungstate. The acid is hydrochloric acid, sulfuric acid or acetic acid. The base (B3) is one of potassium carbonate, potassium hydroxide and/or sodium carbonate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The 2-(alkyl sulfonyl)-4,6-dialkoxy pyrimidine is prepared by: (a) reacting dialkyl malonate and thiourea in the presence of sodium alkoxide and an alcohol to obtain a sodium salt of thiobarbituric acid; (b) alkylating the salt of thiobarbituric acid with alkyl chloride to obtain 2-alkyl thio-4,6-dihydroxypyrimidine; (c) chlorinating the 2-alkylthio-4,6-dihydroxypyrimidine with phosphoryl chloride to obtain 2-alkylthio-4,6-dichloropyrimidine; (d) alkoxylating the 2-alkyl thio-4,6-dichloropyrimidine with sodium alkoxide to obtain 4,6-dialkoxy-2-(alkylthio) pyrimidine; and (e) oxidizing the 4,6-dialkoxy-2-(alkylthio) pyrimidine in the presence of hydrogen peroxide, acetic acid and a catalyst and to obtain 4,6-dialkoxy-2-(alkylsulfonyl) pyrimidine. The step (a) comprises: adding dimethyl malonate and thiourea to methanol to obtain a mass, heating the mass to 50-70 degrees C; incorporating a methanolic solution of sodium methoxide to the mass to obtain a mixture; maintaining the mixture at 50-70 degrees C for 1-5 hours; removing methanol from the mixture by distillation to obtain a second mass; cooling the mass to obtain a cooled mass; filtering the mass to obtain a cake; and washing the cake with methanol followed by drying to obtain a sodium salt of thiobarbituric acid. The step (b) comprises: mixing sodium salt of thiobarbituric acid with sodium hydroxide solution and methanol obtain a mass; adding methyl chloride to the mass; and stirring to obtain 2-methylthio-4,6-dihydroxypyrimidine. The step (c) comprises: mixing 2-methylthio-4,6-dihydroxypyrimidine, phosphorus oxychloride, at least one aromatic hydrocarbon and at least one base (B2) to obtain a mixture; heating the mixture to 40-90 degrees C to obtain a heated mixture; and adding phosphorus oxychloride and chlorine into the heated mixture followed by stirring at 40-60 degrees C to obtain 2-methylthio-4,6-dichloropyrimidine. The step (d) comprises: mixing an alcoholic solution of sodium methoxide, cuprous chloride and sodium iodide to obtain a mixture; cooling the mixture followed by adding 2-methylthio-4,6-dichloropyrimidine 15-25 degrees C to obtain a mass; and heating the mass at 30-50 degrees C to obtain 4,6-dimethoxy-2-(methylthio)pyrimidine. The step (e) comprises: mixing 4,6-dimethoxy-2-(methylthio) pyrimidine, sodium tungstate and acetic acid to obtain a mixture; heating the mixture; and adding hydrogen peroxide to obtain 4,6-dimethoxy-2-(methylsulfonyl) pyrimidine. The 2,6-dihydroxy benzoic acid is prepared by a process (p1) comprising: carboxylating resorcinol in the presence of carbon dioxide and at least one base (B3) in at least one solvent (S2) at 100-200 degrees C to obtain a mixture containing 2,6-dihydroxy benzoic acid, 2,4-dihydroxy benzoic acid and 4,6-dihydroxyisophthalic acid; and acidifying the mixture with at least one acid to obtain 2,6-dihydroxy benzoic acid with purity of greater than 95%, where the acidifying step comprises adjusting the pH of the mixture to less than 1. Preferred Process: The process (p1) comprises: carboxylating resorcinol in the presence of carbon dioxide and at least one base (B3) in at least one solvent (S2) at 100-200 degrees C to obtain a mixture containing 2,6-dihydroxy benzoic acid, 2,4-dihydroxy benzoic acid and 4,6-dihydroxyisophthalic acid; maintaining the mixture at 140-180 degrees C for 1-10 hours; cooling the mixture to obtain a cooled mixture; acidifying the cooled mixture to a pH of 5.5-6 with an acid followed by maintaining at 90-110 degrees C for 1-20 hours to obtain an acidified mass and cooling the mass; adjusting the pH of the mass to 2-3 with an acid followed by filtering, washing and drying to obtain a solid mass and a filtrate; and adding an acid to the filtrate to adjust the pH to 0.8-1 followed by stirring, cooling, filtering, washing and drying to obtain 2,6-dihydroxy benzoic acid having purity of greater than 95% (preferably greater than 99%), where the step of carboxylation is carried out at 140-180 degrees C, the step of carboxylation is carried out in a reactor having a pressure of 5-45 kg/cm2, and the drying step is carried out at 40-70 degrees C. The process (p1) includes the step of decarboxylation of 2,4-dihydroxy benzoic acid and 4,6-dihydroxyisophthalic acid to obtain resorcinol and recycling of the resorcinol. Preferred Components: The solvent (S1) is tetrahydrofuran, dimethylsulfoxide, dimethylformamide, dimethyl acetamide, N-methyl pyrrolidone, sulfolane, monoglyme or diglyme. The 2-(alkyl sulfonyl)-4,6-dialkoxy pyrimidine is 2-(methyl sulfonyl)-4,6-dimethoxy pyrimidine. The dialkyl malonate is dimethyl malonate (preferred), diethyl malonate, di-n-propyl malonate and di-n-butyl malonate. The sodium alkoxide is sodium methoxide. The alkyl chloride is methyl chloride. The 2-alkyl thio-4,6-dihydroxypyrimidine is 2-methyl thio-4,6-dihydroxypyrimidine. The 2-alkyl thio-4,6-dichloropyrimidine is 2-methyl thio-4,6-dichloropyrimidine. The 4,6-dialkoxy-2-(alkylthio) pyrimidine is 4,6-dimethoxy-2-(methylthio)pyrimidine. The 4,6-dialkoxy-2-(alkylsulfonyl)pyrimidine is 4,6-dimethoxy-2-(methyl sulfonyl)pyrimidine. The alcohol is methanol, ethanol, n-propyl alcohol or n-butyl alcohol. The aromatic hydrocarbon is one of monochlorobenzene and/or o-dichlorobenzene. The base (B2) is one of triethylamine, tripropylamine and/or tributylamine. The solvent (S2) is one of toluene, N,N-dimethylformamide, N,N-diethylformamide, ethanol, methanol, acetone and/or water. ACTIVITY - Herbicide.    MECHANISM OF ACTION - None given.    EXAMPLE - Clear solution of 154 g of 2,6-dihydroxy benzoic acid in 500 ml dimethyl sulfoxide was added over 2-3 hours into a mixture of commercial available (60% emulsion in oil) 130 g of sodium hydride in 2 l of dimethyl sulfoxide at 30-32 degrees C. The mass was further stirred for 2 hours at 30-32 degrees C and 480 g of 4,6-dimethoxy-2-(methyl sulfonyl)-pyrimidine was added into it over 2 hours. The reaction was maintained at 30-32 degrees C till completion to get bispyribac sodium. The reaction was monitored by HPLC. The reaction mass was filtered, washed with dimethylsulfoxide. Wet solids were reslurried into 1000 ml of methanol and then in 1000 ml of 75% aqueous methanol. Wet solids were dried in oven to get 435 gm of bispyribac sodium. This bispyribac sodium was reslurried into 1200 ml of toluene at reflux temperature, cooled, filtered and dried to give 385 g of bispyribac sodium (purity 98.7%).