Title: Benzthiazide
CAS Registry Number: 91-33-8
CAS Name: 6-Chloro-3-[[(phenylmethyl)thio]methyl]-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide
Additional Names: 3-[(benzylthio)methyl]-6-chloro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide; 3-[(benzylthio)methyl]-6-chloro-7-sulfamoyl-2H-benzo-1,2,4-thiadiazine 1,1-dioxide; 6-chloro-7-sulfamoyl-3-benzylthiomethyl-2H-1,2,4-benzothiadiazine 1,1-dioxide; benzothiazide
Trademarks: Exna (Wyeth); Fovane (Pfizer)
Molecular Formula: C15H14ClN3O4S3
Molecular Weight: 431.94
Percent Composition: C 41.71%, H 3.27%, Cl 8.21%, N 9.73%, O 14.82%, S 22.27%
Literature References: Prepn: J. M. McManus et al., 136th Am. Chem. Soc. Meet. (Atlantic City, Sept. 1959) Abstr. of Papers, pp 13-O; W. M. McLamore, G. D. Laubach, DE 1137740; eidem, US 3440244 (1962, 1969 both to Pfizer). Pharmacology, toxicity: S. Y. P'an et al., J. Pharmacol. Exp. Ther. 128, 122 (1960).
Properties: Crystals from acetone, mp 231-232° (U.S. patent); also reported as mp 238-239° (P'an). Bitter taste. Practically insol in water. Sol in alkaline solns. LD50 in mice, rats (mg/kg): >5000, >10000 orally; 410, 422 i.v. (P'an).
Melting point: mp 231-232° (U.S. patent); mp 238-239° (P'an)
Toxicity data: LD50 in mice, rats (mg/kg): >5000, >10000 orally; 410, 422 i.v. (P'an)
Therap-Cat: Diuretic, antihypertensive.
Keywords: Antihypertensive; Thiazides and Analogs; Diuretic; Thiazides and Analogs.
Benztropine Mesylate Benzydamine Benzyl Acetate Benzyl Alcohol Benzyl Benzoate

Systematic (IUPAC) name
6-chloro-1,1-dioxo-3-(phenylmethylsulfanylmethyl)- 4H-benzo[e][1,2,4]thiadiazine-7-sulfonamide
Clinical data
AHFS/ International Drug Names
Legal status Prescription only
Routes Oral
Pharmacokinetic data
Bioavailability 60 to 70%
Protein binding 30%
Half-life 5 to 15 hours
Excretion Renal
CAS number 91-33-8 YesY
ATC code None
PubChem CID 2343
DrugBank DB00562
ChemSpider 2253 YesY
UNII 1TD8J48L61 YesY
KEGG D00651 YesY
Chemical data
Formula C15H14ClN3O4S3 
Mol. mass 431.94 g/mol
 N (what is this?)  (verify)

Benzthiazide (BAN/INN, also known as benzothiazide; trade names Aquatag, Dihydrex, Diucen, Edemax, Exna, Foven and others[1]) is a thiazide diuretic used in the treatment of high blood pressure and edema. It is no longer available in the United States.

In the United Kingdom, it was also sold in combination with the potassium-sparing diuretic triamterene under the trade name Dytide.[2] The same combination is still available in Switzerland as Dyrenium compositum.[3]