1,2-Ethanedithiol → HCID 14502136, compound

Participants

Reaction Conditions

Reaction Steps

1,2-ethanedithiol (113 cc) is poured into a suspension of sodium borohydride (52 g) in tetrahydrofuran (1.4 liters), with stirring, in 15 minutes and at a temperature of about 20° C., and then a solution of ethyl (2RS)-2-(2-cyano-10-phenothiazinyl)propionate (296 g) in tetrahydrofuran (1.4 liters) is poured in 15 minutes under the same conditions. At the end of the addition, the reaction mixture is heated for 20 hours at a temperature of about 60° C. After cooling to a temperature of 5° C., a 4N aqueous solution of sodium hydroxide (1 liter) is poured in over 1 hour: a strong evolution of gas is observed. The reaction mixture is then poured into a mixture of a 4N aqueous solution of sodium hydroxide (1 liter) and methylene chloride (3 liters), while stirring. The organic phase is isolated and the aqueous phase is again extracted with methylene chloride (1 liter). The pooled organic phases are washed with a saturated aqueous solution of sodium chloride (2×1 liter), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. The viscous orange oil (290 g) is purified on a column (height: 50 cm; diameter: 8.5 cm) of silica gel (0.2-0.063 mm), eluting successively with methylene chloride (3 liters), then a mixture of methylene chloride and methanol (97.5-2.5 by volume) (4 liters) and with a mixture of methylene chloride and methanol (95-5 by volume) (10 liters) and collecting fractions of 1 liter. Fractions 3 to 15 are pooled and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 30° C. 10-[(2RS)1-hydroxy-2-propyl]- 2-phenothiazinecarbonitrile (169.7 g) is thus obtained in the form of a yellow solid which melts at 123° C.

Provenance & Evidence