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ChemicalBook CAS DataBase List Hydrochlorothiazide
58-93-5

Hydrochlorothiazide synthesis

5synthesis methods
Hydrochlorothiazide, 1,1-dioxide 6-chloro-3,4-dihydro-2H-1,2,4- benzothiadiazin-7-sulfonamide (21.3.4), is synthesized either by cyclization of 4,6-sulfonamido- 3-chloroaniline (21.3.2) using paraformaldehyde, during which simultaneous reduction of the double bond occurs at position C3–C4, or the drug is synthesized by reduction of the same double bond in chlorothiazide (21.3.3) by formaldehyde. This small change in structure increases activity of the drug in comparison with chlorothiazide, and increases its absorbability when used orally.

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Yield:58-93-5 93.9%

Reaction Conditions:

with potassium borohydride;acetic acid in methanol at -10 - 5; for 4 h;Reagent/catalyst;Solvent;

Steps:

2 6-Chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide-1,1-dioxidePreparation of matter

potassium borohydride (3.65 g, 67.6 mmol, 2 eq) was added to methanol (50 mL).The temperature was lowered to 0 to 5 ° C, and acetic acid (8.11 g, 135.2 mmol, 4 eq) was added dropwise at this temperature.After stirring for 1~2h,Cool down to -10 ° C,The compound chlorothiazide (10 g, 33.8 mmol, 1 eq) was added at this temperature.Maintain -10 ~ 5 ° C reaction for 4h,Filter by suction and rinse the filter cake with a small amount of methanol (10 mL).Get about 9.4g of white solid(Yield 93.9%).

References:

CN108658896,2018,A Location in patent:Paragraph 0063; 0067-0069; 0075; 0081; 0088; 0095; 0101

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