In 1956,Chemische Berichte included an article by Goerdeler, Joachim; Ohm, Josef; Tegtmeyer, Otto. Formula: C2HClN2S. The article was titled 《1,2,4-Thiadiazoles. VI. Preparation and properties of 1,2,4- and 1,3,4-thiadiazole》. The information in the text is summarized as follows:
cf. C.A. 51, 2753a. Adding (40 min.) 7 g. NaNO2 in the min. amount of H2O to 5 g. 5-amino-1,2,4-thiadiazole in 150 cc. 37% HCl and a small amount of Cu powder at -10° and stirring the mixture 1.5 hrs. at -10° and 0.5 hr. at 50-60° yield 58% 5-chloro-1,2,4-thiadiazole, b758 122-2.5°, m. -8° to -7°, d20 1.496, nD21 1.5388; HBr in lieu of HCl gives 74% 5-Br analog (I), stars or needles, m. 27.5-8°. 3-Methyl-5-amino-1,2,4-thiadiazole (II) and HBr yield the 3-Me homolog of I, m. 24-5°. Shaking 49.5 g. I and 30.4 g. Et3N in 70 cc. MeOH with 30 g. Raney Ni and H at atm. pressure and 20°, adding 350 cc. Et2O to precipitate the Et3N.HBr, then adding CaCl2 to the filtered solution, and distilling the Et2O solution give 72% 1,2,4-thiadiazole (III), b753 120.7-1.2°, d20 1.3298, nD21.9 1.5316; III.HCl and III.HBr readily sublime; III.H2SO4 is very hygroscopic; III.MeI, m. 164° (decomposition); III.AgNO3 needles, m. 80-1°; III.HgCl2 sublimes on heating; III.0.5 CoCl2, violet needles, soluble in H2O. 3-Me derivative of III, prepared like III from I in 78% yield, b753 131.8-2.9°, d20 1.2104, nD21 1.5149. Heating 3.3 g. I in 10 cc. concentrated H2SO4 2 hrs. on a water bath, pouring the mixture into 50 cc. ice H2O, and extracting with Et2O yield 64% 5-HO derivative of III, m. 120.5°. Treating 1.32 g. I in 5 cc. EtOH with MeNH2, refluxing the mixture 0.5 hr., evaporating it in vacuo, and extracting with Et2O give 92% 5-methylamino derivative of III, m. 58.5-60°. Heating 9.1 g. dry powd. H2NNHCSNH2 and 7 g. anhydrous HCO2H rapidly with stirring 45-60 min. at 140° and pouring the mixture into H2O yield 50-60% formylthiosemicarbazide (IV), m. 173-4° (decomposition), also obtained in 85% yield by stirring 4.5 g. H2NNHCSNH2 and 8.8 g. HCO2Ac 45 min. below 50°. Treating 11.9 g. IV with 23.6 g. AcCl 5-6 hrs. while the reaction is controlled by occasional cooling in H2O, and pouring the mixture into ice H2O give 80% 2-amino-1,3,4-thiadiazole (V), m. 190-1°. Adding an intimate mixture of 10 g. V and 32 g. NaNO2 in small portions to 160 cc. 40% HBr containing a small amount of Cu powder at -10°, stirring the mixture 1 hr. at -5° and 1.5 hrs. at 20°, neutralizing it with cooling with concentrated NaOH, adding NaHSO3 until KI-starch paper is no longer blued, warming the mixture a short time at 60°, extracting the filtered solution 6-7 hrs. with Et2O, and subliming the residue of the Et2O at 56°/12 mm. yield 75-90% 2-bromo-1,3,4-thiadiazole (VI), stout crystals, m. 72-3°; 2-Me homolog, prepared similarly from 2-methyl-5-amino-1,3,4-thiadiazole in 80-90% yield, m. 107.5-8°. Adding (1 hr.) a mixture of 10.1 g. V and 32 g. NaNO2 to 180 cc. 25% HCl containing a small amount of Cu at -10° yields 70-75% 2-Cl analog of VI, m. 32.5-3°. VI and MeNH2 give 80% 2-methylamino-1,3,4-thiadiazole, m. 164.5-65°. Refluxing 2.5 g. VI and 1.2 g. CS(NH2)2 in 10 cc. EtOH 1.5 hrs., adding 1.12 g. KOH in 16 cc. H2O, boiling it a few min., acidifying it, and extracting it with Et2O give 75% 2-mercapto-1,3,4-thiadiazole, m. 143°. Hydrogenating 8.2 g. VI and 5.3 g. Et3N in 40 cc. MeOH at slightly superatm. pressure and 20° with 100 mg. freshly reduced PtO2 with intermediate addition of fresh PtO2 until the theoretical amount of H has been absorbed, evaporating the filtered solution, and triturating the residue with Et2O yield 90% 1,3,4-thiadiazole (VII), b15 86-8°, b13 82-3.5°, b760 204-5° (decomposition), nD20 1.5470, m. 42-3°; 2-Me homolog, prepared similarly in almost 100% yield, b17 93°, b760 200.5-1.3° (decomposition), d20 1.2395, nD20 1.5320, m. 22-2.7° [HCl salt, very hygroscopic crystals, m. 116-19° (decomposition); picrate, yellow needles, m. 103-5° (decomposition); HgCl2 addition compound, m. 151-2° (decomposition); AgNO3 complex, m. 168-9° (decomposition)]. VII.HCl is very hygroscopic; VII.HBr is not hygroscopic; VII picrate, lemon-yellow needles, m. 98° (decomposition); VII.MeI m. 240-1° (decomposition); VII.AgNO3 m. 169°; VII.HgCl2, long shiny needles, m. 124-6° (decomposition). The results came from multiple reactions, including the reaction of 5-Chloro-1,2,4-thiadiazole(cas: 38362-15-1Formula: C2HClN2S)
5-Chloro-1,2,4-thiadiazole(cas: 38362-15-1) is a member of organic chlorides. Organic chlorides are compounds containing a carbon-chlorine bond, which are widely used in the oil field as a wax dissolver. They are generally not present in crude oils and are typically the result of additives, cleaning solutions or chemicals used for oil recovery.Formula: C2HClN2S
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics