Butene, 3,4-dichloro butyn

Since the exocyclic sulfur is more reactive in the ambident anion than in A-4-thiazoIine-2-thione. greater nucleophilic reactivity is to be expected. Thus a large variety of thioethers were prepared in good yields starting from alkylhalides (e.g.. Scheme 38 (54, 91, 111, 166-179). lactones (54, 160), aryl halides (54, 152. 180, 181), acyl chlorides (54. 149, 182-184). halothiazoles (54, 185-190), a-haloesters (149. 152. 177. 191-194), cyanuric chloride (151). fV.N-dimethylthiocarbamoyl chloride (151, 152. 195. 196), /3-chloroethyl ester of acrylic acid (197), (3-dimethylaminoethyl chloride (152). l,4-dichloro-2-butyne (152), 1,4-dichloro-2-butene (152), and 2-chloro-propionitrile (152). A general... 

Moisture must be completely excluded because sodamide readily becomes coated with sodium hydroxide it is thus advisable to prepare the reagent shortly before use by reaction of sodium with anhydrous liquid ammonia192 in the presence of iron(m) chloride or nitrate.190 2-Butyn-l-ol (7) is then obtained in 80% from 3-chloro-2-buten-l-ol (6) by way of its sodium salt, the original starting material being l,3-dichloro-2-butene 193... 

Lithium 4,4 -di-t-butylbiphenylide (LDTBB). 13, 162-163 16, 195-196 17, 164 Lithium-halogen exchange. The reagent has been proven particularly effective for chloro compounds, as shown in the Barbier-type reactions involving chloromethyl ethyl ether, l,4-dichloro-2-butyne and -2-butenes. Vinylic chlorides also readily undergo exchange, and actually 2,3-dichloropropene is converted to the dilithio reagent. ... 

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