Sodium borohydride → HCID 18362118, compound

Participants

Reaction Conditions

Reaction Steps

1236.1 g of crude 2-methylene-3-acetoxy-4,4,4-trichlorobutyrate (91.3%) containing about 2.5% 2-methylene-3-hydroxy-4,4,4-trichlorobutyrate and 747 ml of tetrahydrofuran was charged to a 2-liter flask equipped with a reflux condenser, magnetic stir bar, and a thermometer. 38.0 g of sodium borohydride was added in three portions to the stirred solution. The reaction temperature rose to 32° C. The reaction was heated slowly to 70° C. for three hours. NMR indicated 80% of the starting material was converted into product, butyl 2-methyl-4,4,4-trichlorobut-2-enoate. The reaction was heated for another six hours at 80° C. and the reaction was quenched by removal of tetrahydrofuran and addition of water. The organic layer was separated and GC analysis showed the presence of 79.2% butyl 2-methyl-4,4,4-trichlorobut-2-enoate, 1% butyl 2-methyl-2,4,4-trichlorobut-3-enoate, 6.6% unreacted starting material, butyl 2-methylene-3-acetoxy-4,4,4-trichlorobutyrate, 3% butyl 2-methyl-3-acetoxy-4,4,4-trichlorobutyrate, and 0.5% butyl 2-methylene-3-hydroxy-4,4,4-trichlorobutyrate. Hydrogenated product, butyl 2-methyl-3-acetoxy-4,4,4-trichlorobutyrate, was formed owing to the presence of water or traces of other protonic solvents in the reaction system.

Provenance & Evidence