Sulfur monochloride, reaction with dimethylformamide

Sinclair (92) has described an improved method for the preparation of methyl 6-chloro-6-deoxy- -D-glucopyranoside (137) from methyl a-D-glucopyranoside (11). The reaction was effected with sulfur monochloride S2C12 in N,N-dimethylformamide at room temperature and the... 

The reaction of methyl a-D-glucopyranoside with sulfur monochloride in N,N-dimethylformamide to give the 6-chloro-6-deoxy derivative in 30-35% yield has been described392 it is possible thatN,N-... 

Cyanogen itself is reported to react smoothly with sulfur monochloride to form 3,4-dichloro-l,2,5-thiadiazole 37. The reaction was not exothermic and was readily run by passing cyanogens into an S2CI2 solution in dimethylformamide at 80 °C (1967JOC2823 Scheme 21). 

Halogen atoms have been placed at C-6 of substituted 6-deoxy-hexoses by a variety of interesting ways, and the products provide potential routes to 6-deoxyhexoses. Helferich and coworkers 4 reported a low yield of methyl 6-chloro-6-deoxy-a-D-glucoside which they prepared by reaction of the (suitably protected) corresponding 6-trityl ether with phosphorus pentachloride. Sinclair 44 has provided a convenient procedure for the preparation of the 6-chloro derivative in yields of 30-35% by allowing methyl a-D-glucopyranoside to react with sulfur monochloride, SjClj, in N,/V-dimethylformamide. A much better yield (73%) of the 6-bromo derivative was reported1 in the reaction of methyl 2,3,4-tri-O-benzoyl-6-O-trityl-a-D-altroside with phosphorus tribromide and bromine. 

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