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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2089266Generated: October 31, 2026

Acetic Acid → 6-(2-Aminophenyl)-3-sulfanylidene-3,4-dihydro-1,2,4-triazin-5(2H)-one

https://huagongshe.com/reaction/2089266

Reaction equation

Participants

RoleNameHCIDCharge
ReactantAcetic AcidHCID 176—
ReactantIsatinHCID 7054—
ReactantThiosemicarbazideHCID 2723789—
SolventPotassium HydroxideHCID 14797—
Product6-(2-Aminophenyl)-3-sulfanylidene-3,4-dihydro-1,2,4-triazin-5(2H)-oneHCID 71388686.2%

Reaction Conditions

Temperature115 °C

Reaction Steps

This was prepared by a modified literature procedure (Doleschall, G.; Lempert, K. Tetrahedron 1973, 29, 639-649). Isatin (10 g, 67.96 mmol) was dissolved in ca. 10% aqueous KOH (9.9 g in 100 mL of water) and then treated with thiosemicarbazide (6.28 g; 68.90 mmol). After 1 hour of heating at 115° C. (bath temperature), the reaction mixture was poured over ice and treated with glacial acetic acid drop-wise, till the pH was ca. 5. The yellow fluffy precipitate was filtered, washed copiously with water (8×50 mL) and dried first in air and then under high vacuum to afford 12.9 g of yellow solid.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08436031B2
Source datasetuspto-grants-2013_05
ORD IDord-af0d249e9bf24cbb8dea2515d17a2a1a
Source noteuspto-grants-2013_05