(+/-)-1.1'-BINAPHTHALENE-2,2'-DITHIOL Property

Melting point:

mp 150-151 °C (benzene)

Boiling point:

495.0±40.0 °C(Predicted)

Density 

1.283±0.06 g/cm3(Predicted)

pka

5.83±0.30(Predicted)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H372Causes damage to organs through prolonged or repeated exposure

H413May cause long lasting harmful effects to aquatic life

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

P501Dispose of contents/container to..…

(+/-)-1.1'-BINAPHTHALENE-2,2'-DITHIOL Chemical Properties,Usage,Production

Uses

1,1''-Binaphthyl-2,2''-dithiol is used in the preparation of chiral, atropisomeric organosulfur compounds.

Preparation

the original procedure of 1,1'-Binaphthyl-2,2'-dithiol used Ullman coupling of 1-bromo-2-naphthalenesulfonic acid. The intermediate 1,1′-binaphthalene-2,2′-sulfonic acid can be resolved with strychnine. Lithiation of 2,2′- dibromo-1,1′-binaphthalene with t-butyllithium, quenching with sulfur, and reduction of the resulting disulfide is an alternative preparation of the racemic dithiol. More practical procedures entail Newman-Kwart rearrangement of the thioester derived from binaphthol and dimethylthiocarbamoyl chloride, followed by hydrolysis. Use of enantiomerically pure binaphthol as starting material gives the enantiomerically pure reagent. Another resolution procedure involves enantioselective oxidation of sulfides which can be further transformed into the dithiol.

storage

(+/-)-1,1'-Binaphthyl-2,2'-dithiol oxidizes easily to the disulfide and should be stored under inert atmosphere. Use in a fume hood.