反应详情

A suspension of 5,6-dihydro-1,4-dithiin-2-carboxylic acid (13.1 g) in thionyl chloride (60 cc) is gradually heated to reflux. After 30 minutes under reflux, the solution obtained is concentrated to dryness at 50° C. under reduced pressure (4 kPa) and the oily residue obtained is washed with cyclohexane (2×100 cc). The decanted oil is dried at 50° C. under reduced pressure (4 kPa). 5,6-Dihydro-1,4-dithiin-2-carbonyl chloride (15.8 g) is thereby obtained, and this is used as it is in the following operation.

1. temperatureis gradually heated to reflux
2. temperatureAfter 30 minutes under reflux
3. customthe solution obtained
4. concentrationis concentrated to dryness at 50° C. under reduced pressure (4 kPa)
5. customthe oily residue obtained
6. washis washed with cyclohexane (2×100 cc)
7. customThe decanted oil is dried at 50° C. under reduced pressure (4 kPa)