4-(methylamino)-4-oxobutanoic acid

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

Procedure: 28.5 gm of succinic acid monomethylamide (0.216 mol) were melted with 35.4 gm of H3PO3 (0.432 mol) at 70° C. and then slowly mixed with 37.8 ml of PCl3 (0.432 mol). After an additional 5 hours at 70° C., the product was hydrolyzed with 300 ml of H2O. Filtration with activated carbon at the boiling point yielded a clear solution from which the N-methyl-pyrrolidone-5,5-diphosphonic acid was precipitated with ethanol and acetone. Crude yield 4.2 gm (7% of the theory). Filtration with activated carbon at the boiling point

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

Procedure: 28.5 gm of succinic acid monomethylamide (0.216 mol) were melted with 35.4 gm of H3PO3 (0.432 mol) at 70° C. and then slowly mixed with 37.8 ml of PCl3 (0.432 mol). After an additional 5 hours at 70° C., the product was hydrolyzed with 300 ml of H2O. Filtration with activated carbon at the boiling point yielded a clear solution from which the N-methyl-pyrrolidone-5,5-diphosphonic acid was precipitated with ethanol and acetone. Crude yield 4.2 gm (7% of the theory). Filtration with activated carbon at the boiling point

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

Procedure: 28.5 gm of succinic acid monomethylamide (0.216 mol) were melted with 35.4 gm of H3PO3 (0.432 mol) at 70° C. and then slowly mixed with 37.8 ml of PCl3 (0.432 mol). After an additional 5 hours at 70° C., the product was hydrolyzed with 300 ml of H2O. Filtration with activated carbon at the boiling point yielded a clear solution from which the N-methyl-pyrrolidone-5,5-diphosphonic acid was precipitated with ethanol and acetone. Crude yield 4.2 gm (7% of the theory). Filtration with activated carbon at the boiling point

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

Procedure: Synthesis in analogy to the General Method 1 starting from (3aS,4R,7aS)-4-hydroxy-4-m-tolylethynyl-octahydro-indole-1-carboxylic acid methyl ester and N-methylsuccinamic acid to yield (3aR,4S,7aR)-methyl 4-(4-(methylamino)-4-oxobutanoyloxy)-4-(m-tolylethynyl)octahydro-1H-indole-1-carboxylate. MS [M+H]=427; RT=1.06 min; UPLC Method I

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

Procedure: 28.5 gm of succinic acid monomethylamide (0.216 mol) were melted with 35.4 gm of H3PO3 (0.432 mol) at 70°C and then slowly mixed with 37.8 ml of PCl3 (0.432 mol). After an additional 5 hours at 70°C, the product was hydrolyzed with 300 ml of H2O. Filtration with activated carbon at the boiling point yielded a clear solution from which the N-methylpyrrolidone-5,5-diphosphonic acid was precipitated with ethanol and acetone. Crude yield 4.2 gm (7% of the theory). Filtration with activated carbon at the boiling point

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

Procedure: 28.5 gm of succinic acid monomethylamide (0.216 mol) were melted with 35.4 gm of H3PO3 (0.432 mol) at 70° C. and then slowly mixed with 37.8 ml of PCl3 (0.432 mol). After an additional 5 hours at 70° C., the product was hydrolyzed with 300 ml of H2O. Filtration with activated carbon at the boiling point yielded a clear solution from which the N-methyl-pyrrolidone-5,5-diphosphonic acid was precipitated with ethanol and acetone. Crude yield 4.2 gm (7% of the theory). Filtration with activated carbon at the boiling point