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Part-IExperimentalA solution of thioglycolic acid (9.2 gm; 0.1 mole) in 50 ml of methanol was cooled in icebath. Dry HCl gas was bubbled in this solution over 3-4 hrs. The reaction mixture waskept overnight, undisturbed at room temperature. Next day, the mixture was boiled onwater bath for 2-3 hrs, cooled to room temperature, quenched with ice water (50 ml),extracted with chloroform and washed with NaHCO 3 (10% w/v) and water and dried(Na 2 SO 4 ). On concentrating this organic extracts, gave yellow colored liquid.B.P. : 120-124 o C (120-124 o C) 12 ; Yield: 90%Mol. Formula : C 3 H 6 O 2 S; Mol. Wt. 106c. Synthesis of methyl 3-amino-4-methoxybenzo[b]thiophene 2-carboxylate 13To a cold solution of 2-nitro-6-methoxybenzonitrile (53 gm; 0.30 mole) and methylthioglycolate in 60 ml of dry dimethylformamide (31.8 gm; 0.30 mole), an aq. solution ofKOH (3.0 gm in 15 ml of water) was added with continuous stirring. The solution wasstirred at 0 o C for 3 hrs and then diluted with ice-water. The solid obtained was filtered,dried and recrystallized from ethanol-water mixture to yield colorless needles.M.P. : 140-143 o C (147-148 o C) 13 ; Yield: 80%Mol. Formula : C 11 H 11 NO 3 S; Mol. Wt. 237.2IR(KBr)cm -1 : 3484, 3376(γ NH ), 2947(γ C-H ), 1670(γ C=O ).1 H NMR (CDCl 3 )δppm : 3.90 (3H, s, CH 3 at COOCH 3 ), 3.95 (3H, s, CH 3 of OCH 3 ), 6.75(2H, s, br, NH 2 at 3), 7.21-7.40 (3H, m, Ar-H).MS m/e : 238(M+1), 237(M + ), 222, 206.17. Synthesis of 5-amino-4-carboxamide-3-(methylthio)pyrazole 14 (Ixvii)a. Synthesis of ethyl-2,2-di-(methylthio)methylene cyanoacetamideIn an ice cold solution of KOH in 10 ml of water was added 30 ml dimethylformamideslowly with stirring and cooling. To this, cyanoacetamide and carbon disulphide wereadded with continuous stirring and cooling. Thereafter, the reaction mixture was cooledand stirred for 1 hr at 5-10 o C and again stirred for 1 hr at room temperature. The reactionmixture was further cooled to 0-5 o C and to this, dimethylsulphate was added dropwisewhile maintaining the temperature below 20 o C. Stirring was continued further for 2 hrsand thereafter the reaction mixture was allowed to stand overnight at room temperature.176