Triphenylphosphine → HCID 86742762, compound

Participants

Reaction Steps

Also in accordance with Scheme 1 and starting with the reaction of t-butyloxycarbonyl-L-threonine (1b) with benzophenone hydrazone (2) in the presence of 2-ethoxy-1(2H)-quinolinecarboxylic acid ethyl ester the hydrazide derivative N-(t-butyloxycarbonyl)-L-threonine-2-(2-diphenylmethylene)hydrazide (3b) was obtained. Ring closure of (3b) as described above with diethyl azodicarboxylate and triphenylphosphine gave the β-lactam, t-butyl (S)-[1-[(diphenylmethylene)amino]-2-(S)-methyl-4-oxo-3-azetidinyl)-carbamate (4b). Catalytic hydrogenation of (4b) gave the N-amino compound t-butyl 1-amino-2-(S)-methyl-4-oxo-3-(S)-azetidinylcarbamate (5b) which was reacted with benzyl glyoxylate (6) to give the imino derivative benzyl [[4(S)-methyl-3(S)-[(t-butoxycarbonyl)amino]-2-oxo]imino]acetate (7b). Catalytic reduction of (7b) gave the amino derivative 4(S)-methyl-[[3(S)-[[(t-butyloxycarbonyl]amino]-2-oxo-1-azetidinyl]imino]acetic acid (8b) which was treated with trifluoroacetic acid to give the amino acid, [[(S)-3-amino-4-oxo-2-(S)-methyl-1-azetidinyl]iminoacetic acid trifluoroacetate (9b). Then condensation of the trimethylsilyl derivative (10b) with the activated ester of 2-(2-amino-4-thiazolyl)-2-methoxyiminoacetic acid (11) gave the desired monobactam derivative (S)-3-[2-(2-amino-4-thiazolyl)]-(Z)-2-methoxyiminoacetylamino-2-(S)-methyl-4-oxo-1-azetidinyliminoacetic acid (12b). ##STR3##

Provenance & Evidence