ChemicalBook CAS DataBase List 2-Mercapto-5-methyl-1,3,4-thiadiazole

2-Mercapto-5-methyl-1,3,4-thiadiazole synthesis

6synthesis methods

Product Name:2-Mercapto-5-methyl-1,3,4-thiadiazole
CAS Number:29490-19-5
Molecular formula:C3H4N2S2
Molecular Weight:132.21

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29490-19-5
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Yield:29490-19-5 84.2%

Reaction Conditions:

with SO₄²^-/TiO₂-SnO₂-Al₂O₃ solid super acid catalyst in tetrahydrofuran at -5 - 0; for 3.5 h;

Steps:

1.2 Step 2: Synthesis of 5-methyl-2-mercaptothiadiazole (MMTD)
Add 240g of SO42-/TiO2-SnO2-Al2O3 solid acid catalyst with a particle size of 3mm and 500g of tetrahydrofuran to a 500ml reaction flask. Cool down to below 0°C, control -5-0°C, slowly add 80g of PAD solid, about 2.5 hours After the addition is complete, stir for another 1 hour. The end of the reaction is monitored by HPLC (raw material residue ≤0.5%). After the reaction is completed, filter. The filtered solid acid catalyst is washed with 500g water and used directly in the next reaction. The filtrate is evaporated under reduced pressure at 40°C. Remove solvent to dryness. Add 194ml of purified water to the residue, slowly drop 176g of 10% sodium hydroxide solution into it at 15-20, add it within 0.5 hours, until the residue is completely dissolved, then add 2.5g of activated carbon to the reaction system. Decolorize at 15-20°C for 0.5 hours, filter, and wash the filter cake with 50ml purified water. At 15-20, slowly add concentrated hydrochloric acid to the obtained filtrate to pH=5.7, add seed crystals, and drop the concentrated hydrochloric acid to pH=1.5 when the crystals are grown, continue to cool the reaction solution to 0-5, and stir for 0.5 hours , Filter, wash with ice water several times to pH=5.0, get MMTD wet product. Vacuum drying at 50°C for 4.0 hours, turning the material once, heating to 70°C and continuing vacuum drying for 8.0 hours, detecting moisture content ≤0.5%, and discharging. The obtained material is 47.3g, the yield is 84.2%, and the HPLC is ≥99.95%. Melting point 185.7-187.7°C, moisture content 0.41%

References:

Shandong Jincheng Kerui Chemical Co., Ltd.;Song Guanghui;Hou Lewei;Sun Zhiyuan;Zhang Lin;Guo Lei CN112110874, 2020, A Location in patent:Paragraph 0020; 0023-0025

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