Diethoxyphosphinyl thioamide

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 250-mL round-bottom flask equipped with a thermometer, drying tube (calcium chloride) was charged with 10.0 g (0.1019 mol) of cyclobutyl methyl ketone (SEA C Lot 01) and 80 mL of methanol. The mixture was cooled to 5° C., and 0.8 mL of a 30% solution of hydrogen bromide in acetic acid was added, followed by 5.0 mL (0.09705 mol) of bromine, during a period of 10 min, while the temperature of the slight exotherm was maintained at about 5° C. The mixture was stirred for 4 hours at 5° C. (Decolorization from dark brown to light orange occurred after 75 minutes). To this mixture was added dropwise 10.0 mL of water, with cooling in an ice bath (the temperature rose from 5° to 10° C.). After the addition, the mixture was stirred at room temperature for a period of 45 minutes. To this mixture was added 20.45 g (0.0968 mol) of crude compound of Example 1 as a powdered solid which dissolved gradually with concomitant decolorization of the yellow solution. The reaction temperature during the addition of the compound of Example 1 was maintained at 30° C. by an ice bath. The mixture was stirred at room temperature overnight. At that time, the compound of Example 1 was no longer detectable (TLC, Merck silica gel 60, F-254; 95:5 ethyl acetate-methanol). The mixture was rendered basic with concentrated ammonium hydroxide solution while the temperature was maintained at 20° C. with an ice bath and was then evaporated. The residue was taken up in 150 mL of ethyl acetate. This solution was washed with 100 mL of water and the aqueous phase was reextracted with 75 mL of ethyl acetate. 50 mL of brine was used to wash, in succession, the first and the second ethyl acetate solutions. The ethyl acetate solutions were combined and dried over sodium sulfate. After solvent evaporation and drying at 60° C. at 10 torr, there was obtained 28 g of crude [(4-cyclobutyl-2-thiazolyl)methyl]phosphonic acid diethyl ester as a dark oil, 99.83% pure (HPLC); 100% yield based on the compound of Example 1 used. A 250-mL round-bottom flask equipped with a thermometer drying tube (calcium chloride) was maintained at about 5° C with cooling in an ice bath (the temperature rose from 5° to 10° C. After the addition the mixture was stirred at room temperature for a period of 45 minutes dissolved gradually with concomitant decolorization of the yellow solution was maintained at 30° C. by an ice bath The mixture was stirred at room temperature overnight was maintained at 20° C. with an ice bath was then evaporated This solution was washed with 100 mL of water to wash, in succession dried over sodium sulfate After solvent evaporation drying at 60° C. at 10 torr

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 250-mL round-bottom flask equipped with a dry-ice condenser and drying tube filled with potassium hydroxide pellets, was charged with 50.0 g (0.2822 mol) of diethyl cyanomethyl phosphonate (Aldrich Lot HY0151136Y), 79.0 mL (0.5668 mol) of triethylamine and 53.0 mL (0.6553 mol) of pyridine. To the resulting solution was added 3.3 g (0.390 mol) of hydrogen sulfide via submerged tube. The reaction flask was stoppered and stirred overnight (small samples were withdrawn, evaporated at 55° C. and 10 torr, redissolved in CDCl3 and checked by NMR spectroscopy for completion of reaction). After about 16 hours, the reaction mixture was evaporated at 55° C. and 10 torr, the crystalline residue was taken up in 200 mL of dichloromethane and the resulting solution was washed with 200 mL of a 1:1 water-saturated sodium chloride solution. The aqueous phase was reextracted with 100 mL of dichloromethane. 50 mL of 1:1 water-saturated sodium chloride solution was used to wash the first extract and then the second. The extracts were combined, dried over sodium sulfate, and evaporated to yield 50.46 g of (2-amino-2-thioxoethyl)phosphonic acid diethyl ester as an off-white, crystalline material after drying at 45° C. and 10 tort, 85% yield. A 250-mL round-bottom flask equipped with a dry-ice condenser drying tube filled with potassium hydroxide pellets (small samples were withdrawn, evaporated at 55° C. and 10 torr, redissolved in CDCl3 and checked by NMR spectroscopy for completion of reaction) After about 16 hours the reaction mixture was evaporated at 55° C. the resulting solution was washed with 200 mL of a 1:1 water-saturated sodium chloride solution to wash the first extract dried over sodium sulfate evaporated