Antithrombotic agents

A compound of formula I

• wherein
• A3, A4, A5 and A6, together with the two carbons to which they are attached, complete a substituted indole ring in which A3 and A4 together form a fused benz ring, and A5 and A6 together form —NH—;
• wherein
• L1 is —CO—NH— such that —L1—Q1 is —CO—NH—Q1;
• Q1 is phenyl, 2-furanyl, 2-thienyl, 4-thiazolyl, 2-pyridyl, 2-naphthyl, 1,2-dihydrobenzofuran-5-yl, 1,2-dihydrobenzofuran-6-yl or 1,2-benzisoxazol-6-yl in which the phenyl may bear a 2-fluoro substituent or may bear one, two or three substituents at the 3-, 4- or 5-position(s) independently selected from halo, cyano, carbamoyl, aminomethyl, methyl, methoxy, difluoromethoxy, hydroxymethyl, formyl, vinyl, amino, hydroxy and 3,4-methylenedioxy, the 2-furanyl or 2-thienyl may bear a chloro or methyl substituent at the 5-position, the 4-thiazolyl may bear an amino substituent at the 2-position, the 2-pyridyl may bear an amino substituent at the 6-position, and the 1,2-benzisoxazol-6-yl may bear a chloro or methyl substituent at the 3-position;
• or —CO—Q1 is cyclopentenylcarbonyl or cyclohexenylcarbonyl;
• R2 is —L2A—Q2A, —L2B—Q2B, —L2C—Q2C or —L2D—Q2D wherein
• L2A is a direct bond;
• and
• Q2A is
• in which D is carbonyl or —CHRk— in which Rk is hydrogen, hydroxy, (1-6C)alkoxy or —CH2—Rj in which Rj is carboxy, [(1-4C)alkoxy]carbonyl or carbamoyl which may bear one or two (1-2C)alkyl substituents on the nitrogen;
• and one of Rm and Rn is hydrogen and the other is amino, bromo, (1-4C)alkyl or (1-4C)alkoxy, or Rm and Rn together form a benz ring;
• L2B is —NH—CO— such that —L2B—Q2B is —NH—CO—Q2B;
• and
• Q2B is
• in which Ro is hydrogen, halo, (1-6C)alkyl, (1-4C)alkoxy, benzyloxy or (1-4C)alkylthio;
• and Rp is 1-hydroxyethyl, 1-hydroxy-1-methylethyl, 1-methoxy-1-methylethyl, 4-piperidinyl, 4-pyridinyl, dimethylaminosulfonyl or —J—Rq in which J is a single bond, methylene, carbonyl, oxo, —S(O)q— (wherein q is 0, 1 or 2), or —NRr— (wherein Rr is hydrogen or methyl);
• and Rq is (1-6C)alkyl, phenyl, 3-pyridyl or 4-pyridyl;
• L2C is —NRv—CO—X— or —NRv—CS—Y— such that —L2C—Q2C is —NRv—CO—X—Q2C or —NRv—CS—Y—Q2C in which X is —(CH2)x— (wherein x is 0, 1 or 2), —NRw—, NRw—CH2—, —O—, —O—CH2— or —S—CH2—;
• Y is —NRw—CH2— or —O—CH2—;
• and each of Rv and Rw is independently hydrogen, benzyl or (1-6C)alkyl which is not branched at the α-position;
• and
• Q2C is 1-(4-pyridyl)piperidin-4-yl, 1-(4-pyridyl)piperidin-3-yl or 1-(4-pyridyl)pyrrolidin-3-yl in which the pyridyl may bear a substituent at its 2-position selected from cyano, aminomethyl, carboxy, hydroxymethyl and (1-2C) alkyl;
• L2D is —NH—CO— such that —L2D—Q2D is —NH—CO—Q2D;
• and
• Q2D is selected from 4-(4-pyridinyl)benzyloxy, 9-oxo-9H-fluoren-3-yl, benzo[b]thiophen-2-yl (which may bear a chloro, methyl or methoxy substituent), benzofuran-2-yl (which may bear a chloro, methyl or methoxy substituent), 4-(4-morpholinyl)-4-oxobutyl, and 4-piperidinyl or 3,4-didehydropiperidin-4-yl (either one bearing a substituent at the 1-position selected from methylsulfonyl, phenylsulfonyl, (1-5C)alkyl, (4-7C)cycloalkyl, tetrahydropyran-4-yl, 4-thiacyclohexyl and —CH2—Rz in which Rz is isopropyl, cyclopropyl, phenyl, furyl, thienyl, 2-thiazolyl, or pyridyl in which the phenyl may bear one or two substituents independently selected from halo, cyano, hydroxy, methoxy, acetoxy, benzyloxy, amino, acetylamino, nitro and 3,4-methylenedioxy, and the thienyl or furyl may bear a methyl or nitro substituent);
• or a prodrug of the compound of formula I;
• or a pharmaceutically acceptable salt of the compound of formula I or prodrug thereof.