Hexachloroethane → 5-Chlorothieno[2,3-d][1,2,3]thiadiazole-6-carboxylic acid

HRID 2395244Notes

Reaction equation

C([Li])CCC.[Li+].CC([N-]C(C)C)C.[S:14]1[C:18]2[C:19]([C:22]([OH:24])=[O:23])=[CH:20][S:21][C:17]=2[N:16]=[N:15]1.[Cl:25]C(Cl)(Cl)C(Cl)(Cl)Cl>O1CCCC1.O>[Cl:25][C:20]1[S:21][C:17]2[N:16]=[N:15][S:14][C:18]=2[C:19]=1[C:22]([OH:24])=[O:23]

Participants

Conditions

Temperature: -20 °C

Procedure

79 ml (201.6 mmol) of n-butyllithium (1.6M in hexane) are added at -30° C., under nitrogen, to a solution of 20.4 g (201.6 mmol) of diusopropylamine in 200 ml of tetrahydrofuran (THF). After 20 minutes' stirring at -20° C., the LDA solution so prepared is added dropwise at -90° C., under nitrogen, by means of a capillary, to a suspension of 15.0 g (80.6 mmol) of thieno[2,3-d]1,2,3-thiadiazole-6-carboxylic acid in 150 ml of THF. After 90 minutes' stirring at -50° C., a solution of 42.0 g (177.2 mmol) of hexachloroethane in 70 ml of THF is added at -90° C. and the reaction mixture is heated to room temperature within a period of 2 hours. Then the reaction mixture is poured onto 2 litres of water, the aqueous phase is extracted with diethyl ether and acidified with concentrated hydrochloric acid, and the product is isolated by filtration. There are obtained 17.55 g of light-brown solid having a melting point of 255°-265° C. (decomposition).

Workup

stirringAfter 90 minutes' stirring at -50° C.
temperaturethe reaction mixture is heated to room temperature within a period of 2 hours
extractionthe aqueous phase is extracted with diethyl ether
customthe product is isolated by filtration

Sources & evidence

ORD record: ord-6a3d7e26d5fb4e329c937cd0cd50e51a
Source dataset: uspto-grants-1998_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05814629

Reaction notes

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