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US 5,206,373 AGranted
Process for preparing fibrinogen receptor antagonists
AssigneeMerck & Co., Inc.
InventorsJohn Y. L. Chung, David L. Hughes, Dalian Zhao
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Abstract
The invention is a highly efficient synthesis for making compounds of the formula: ##STR1## wherein: R.sup.1 is a six member saturated or unsaturated heterocyclic ring containing one or two heterocyclic atoms wherein the heteroatoms are N; or NR.sup.6, wherein R.sup.6 is H or C.sub.1-10 alkyl; m is an integer from two to six; and R.sup.4 is aryl, C.sub.1-10 alkyl, or C.sub.4-10 aralkyl.
Claims4
A process for preparing compounds of the following formula:
- ##STR13## wherein:
- R.sup.1 is 4-piperidinyl or 4-pyridinyl;
- m is an interger from two to six;
- and
- R.sup.4 is aryl, C.sub.1-10 alkyl, or C.sub.4-10 aralkyl,
- according to the process steps whereby ##STR14## tyrosine or tyrosine-derivative (1-1) is subjected to bis(trimethylsilyl) trifluoroacetamide (BSTFA) mediated sulfonylation, using R.sup.4 SO.sub.2 Cl, to give the corresponding sulfonamide (1-2);
- ##STR15## R is 4-pyridinyl, methylated 4-picoline (1-3) is reacted with n-BuLi, before quenching with a straight chain alkyl group having Br at one end and Cl at the other end, to yield ##STR16## (1-2) is added to (1-4) and subjected to phenolic O-alkylation in aqueous alkaline hydroxide in a highly polar aprotic solvent;
- and when R.sup.1 is optionally 4-piperidinyl, further selectively hydrogenating product (1-5) using Pd/C in acetic acid.
5 more elements
Dependencies are inferred from the claim text.