N-Hydroxysuccinimide → 8-(3-(N-alanyl)amino-pyrrolidinyl)-4H-quinolizin-4-one-3-carboxylic acid

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Reaction Steps

3-Amino-1-benzylpyrrolidine (I. Sumio and T. Matsuo, Japanese Kokai JP 5328161, published Mar. 16, 1978) is coupled to N-t-butoxycarbonyl alanine (Boc-Ala) using conventional N-hydroxysuccinimide coupling procedures. The 1-benzyl group is removed by hydrogenolysis in methanol using palladium on carbon catalyst. The 3-(N-Boc-alanyl)aminopyrrolidine is then reacted with ethyl 8-chloro-1-ethyl-4H-quinolizin-4-one-3-carboxylate, the product of Step 3 of Example 62, as described in Step 4 of Example 62 replacing 3-(N-t-butoxycarbonylaminopyrrolidine) with 3-(N-Boc-alanyl)aminopyrrolidine, to give 8-(3-(N-alanyl)amino-pyrrolidinyl)-4H-quinolizin-4-one-3-carboxylic acid with the nitrogen of the amino acid protected with a Boc group. The Boc protecting group is removed by standard hydrolysis using trifluoroacetic acid and dilute aqueous hydrochloric acid.

Provenance & Evidence