or a pharmaceutically acceptable salt thereof, wherein

HET is one of the following heterocycles:

R¹ is

(a) H;

(b) C₁-C₆-alkyl, C₂-C₄-alkenyl, C₂-C₄-alkynyl, C₃-C₆-cycloalkyl, or C₁-C₄-alkyl-[C₃-C₆-cycloalkyl], any of which is optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2—(C₁-C₄)alkyl, O—CONR^aR^b, NR^aR^b, N(R^a)CONR^aR^b, COO—(C₁-C₄)alkyl, COOH, CN, CONR^aR^b, SO₂NR^aR^b, N(R^a)SO₂NR^aR^b, —C(═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl or piperazinyl;

(c) —O—C₁-C₆-alkyl, —O—C₃-C₆-cycloalkyl, —S—C₁-C₆-alkyl or —S—C₃-C₆-cycloalkyl, any of which is optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2—(C₁-C₄)alkyl, O—CONR^aR^b, NR^aR^b, N(R^a)CONR^aR^b, COO—(C₁-C₄)alkyl, COOH, CN, CONR^aR^b, SO₂NR^aR^b, N(R^a)SO₂NR^aR^b, —C (═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl or piperazinyl;

(d) —C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl, or —O—C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl;

(e) —OH;

(f) —O-aryl, or —O—C₁-C₄-alkyl-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO —OR^a, viii) —C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C—;

(g) —OCON(R^a)(R^b), or —OSO₂N(R^a)(R^b);

(h) —SH, or —SCON(R^a)(R^b);

(i) NO₂;

(j) NR^aR^b, —N(COR^a)R^b, —N(SO₂R^a)R^b, —N(R^a)SO₂N(R^a)₂, —N(OR^a)CONR^aR^b, —N(R^a)SO₂R^a or —N(R^a)CON(R^a)₂;

(k) —CH(OR^a)R^a, —C(OR^b)CF₃, —CH(NHR^b)R^a, —C(═O)R^a, C(═O)CF₃, —SOCH₃, —SO₂CH₃, COOR^a, CN, CONR^aR^b, —COCONR^aR^b, —SO₂NR^aR^b, —CH₂O—SO₂NR^aR^b, SO₂N(R^a)OR^a, —C(═NH)NH₂, —CR^a═N—OR^a, CH═CHCONR^aR^b;

(l) —CONR^a(CH₂)_0-2C(R^a)(R^b)(CH₂)_0-2CONR^aR^b;

(m) tetrazolyl, tetrazolinonyl, triazolyl, triazolinonyl, imidazolyl, imidozolonyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrazolonyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, or phenyl, any of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)R^a, v) C₁-C₆-alkyl, vi) —O—R^a, vii) —NR^aR^b, viii) —C₀-C₄-alkyl-CO—OR^a, ix) —(C₀-C₄-alkyl) -NH—CO—OR^a, x) —(C₀-C₄-alkyl)-CO—NR^aR^b, xi) —S(O)_0-2R^a, xii)—SO₂NR^aR^b, xiii) —NHSO₂R^a, xiv) —C₁-C₄-perfluoroalkyl, and xv) —O—C₁-C₄-perfluoroalkyl;

(n) —C(R^a)═C(R^b)—COOR^a, or —C(R^a)═C(R^b)—CONR^aR^b;

(o)

(p) piperidin-1-yl, morpholin-1-yl, pyrrolidin-1-yl, piperazin-1-yl or 4-susbstituted piperazin-1-yl, any of which is optionally substituted with 1-3 substituents selected from i) —CN, ii) —C(═O)(R^a), iii) C₁-C₆-alkyl, iv) —OR^a, v) —NR^aR^b, vi) —C₀-C₄-alkyl -CO—OR^a, vii) —(C₀-C₄-alkyl)-NH—CO—OR^a, viii) —(C₀-C₄-alkyl)-CON(R^a)(R^b), ix) —SR^a, x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a xiii) —C₁-C₄-perfluoroalkyl and xiv) —O—C₁-C₄-perfluoroalkyl;

R^a is

(a) H;

(b) C₁-C₄-alkyl, optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2—(C₁-C₄)alkyl, —OCONH₂, —OCONH(C₁-C₄alkyl), —OCON(C₁-C₄alkyl)(C₁-C₄alkyl), —OCONHC₁-C₄alkyl-aryl), —OCON(C₁-C₄alkyl) (C₁-C₄alkyl-aryl), NH₂, NH(C₁-C₄alkyl), N(C₁-C₄alkyl)(C₁-C₄alkyl), NH(C₁-C₄alkyl-aryl), N(C₁-C₄alkyl)(C₁-C₄alkyl-aryl), NHCONH₂, NHCONH(C₁-C₄alkyl), NHCONH(C₁-C₄alkyl-aryl), —NHCON(C₁-C₄alkyl)(C₁-C₄alkyl), NHCON (C₁-C₄alkyl)(C₁-C₄alkyl-aryl), N(C₁-C₄alkyl)CON(C₁-C₄alkyl)(C₁-C₄alkyl), N(C₁-C₄alkyl)CON(C₁-C₄alkyl)(C₁-C₄alkyl-aryl), COO—(C₁-C₄-alkyl), COOH, CN, CONH₂, CONH(C₁-C₄alkyl), CON(C₁-C₄alkyl)(C₁-C₄alkyl), SO₂NH₂, SO₂NH (C₁-C₄alkyl), SO₂NH(C₁-C₄alkyl-aryl), SO₂N(C₁-C₄alkyl)(C₁-C₄alkyl), NHSO₂NH₂, —C(═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl or piperazinyl;

(c) C₀-C₄-alkyl-(C₁-C₄)-perfluoroalkyl; or

(d) —C₁-C₄-alkyl-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(C₁-C₄-alkyl), v) —O(C₁-C₄-alkyl), vi) —N(C₁-C₄-alkyl)(C₁-C₄-alkyl), vii) —C_1-10alkyl, and viii) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C—;

R^b is

(a) H; or

(b) C₁-C₆-alkyl, optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2—(C₁-C₄)alkyl, —OCONH₂, —OCONH(C₁-C₄alkyl), NH₂, NH(C₁-C₄alkyl), N(C₁-C₄alkyl)(C₁-C₄alkyl), NHCONH₂, NHCONH (C₁-C₄alkyl), —NHCON(C₁-C₄alkyl)(C₁-C₄alkyl), COO—(C₁-C₄-alkyl), COOH, CN, or CONH₂;

R² is:

(a) H;

(b) —C₁-C₄-alkyl, —C₃-C₆-cycloalkyl or —C₁-C₄-alkyl-(C₃-C₆)-cycloalkyl, optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2—(C₁-C₄)alkyl, O—CONR^aR^b, NR^aR^b, N(R^a)CONR^aR^b, COO—(C₁-C₄)alkyl, COOH, CN, CONR^aR^b, SO₂NR^aR^b, N(R^a)SO₂NR^aR^b, —C(═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl or piperazinyl;

(c) —C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl;

(d) aryl or —(C₁-C₄-alkyl)-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —(C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C (O)—, —CH(OH)—, —C═C—, or —C≡C—;

(e) —C(═O)(R^a), —CONR^aR^b, COO—C₁-C₄)alkyl, —SO₂R^a, N(R^a)COR^a, —SO₂N(R^a)(R^b);

R³ is

(a) H;

(b) —C₁-C₄-alkyl, —C₃-C₆-cycloalkyl or —C₁-C₄-alkyl-(C₃-C₆)-cycloalkyl, optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, S(O)_0-2-(C₁-C₄)alkyl, O—CONR^aR^b, NR^aR^b, N(R^a)CONR^aR^b, COO—(C₁-C₄)alkyl, COOH, CN, CONR^aR^b, SO₂NR^aR^b, N(R^a)SO₂NR^aR^b, —C(═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl or piperazinyl;

(c) —C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl;

(d) aryl or —(C₁-C₄-alkyl)-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —(C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C—;

(e) —O—C₁-C₄-alkyl, —O—C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl, —O-aryl or —O(C₁-C₄-alkyl)-aryl;

(f) —C(═O)(R^a), —SO₂R^a, —SO₂N(R^a)(R^b), CN, NR^aR^b, NO₂, F, Cl, Br, I, OH, OCONR^aR^b, O(C₁-C₄-alkyl)CONR^aR^b, —OSO₂NR^aR^b, COOR^a, N(R^a)COR^a, or CONR^aR^b;

R⁴ and R⁵ each independently is:

(a) H;

(b) —C₁-C₆-alkyl, —C₂-C₆-alkenyl, —C₂-C₆-alkynyl or —C₃-C₆-cycloalkyl, any of which is optionally substituted with one or more of the following substituents: F, CF₃, —O—(C₁-C₄)alkyl, CN, —N(R^a)(R^b), —N(R^a)CO—(C₁-C₄)alkyl, COOR^b, CON(R^a)(R^b) or phenyl;

(c) —O—C₀-C₆-alkyl, —O-aryl, or —O—C₁-C₄-alkyl-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —(C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C—;

(d) —C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl, or —O—C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl; or

(e) CN, NH₂, NO₂, F, Cl, Br, I, OH, OCON(R^a)(R^b)O(C₁-C₄-alkyl)CONR^aR^b, —OSO₂N(R^a)(R^b), COOR^b, CON(R^a)(R^b), or aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —(C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)—CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C; and

R⁶, R⁷ and R⁸ each independently is:

(a) H;

(b) C₁-C₆-alkyl, C₂-C₄-alkenyl, C₂-C₄-alkynyl or C₃-C₆-cycloalkyl, any of which is optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, OCON(R^a)(R^b), NR^aR^b, COOR^a, CN, CONR^aR^b, N(R^a)CONR^aR^b, N(R^a)SO₂NR^aR^b, SO₂NR^aR^b, S(O)_0-2(C₁-C₄-alkyl), —C(═NH)NH₂, tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl, or piperazinyl;

(c) —O—C₁-C₆-alkyl, —O—C₃-C₆-cycloalkyl, —S—C₁-C₆-alkyl or —S—C₃-C₆-cycloalkyl, any of which is optionally substituted with one or more of the following substituents: F, CF₃, OH, O—(C₁-C₄)alkyl, NH₂, NH(C₁-C₄-alkyl), N(C₁-C₄-alkyl)₂, COOH, CN, CONH₂, CONH(C₁-C₄-alkyl), CONH(C₁-C₄-alkyl)₂, SO₂NH₂, SO₂NH(C₁-C₄-alkyl), tetrazolyl, triazolyl, imidazolyl, oxazolyl, oxadiazolyl, isooxazolyl, thiazolyl, furyl, thienyl, pyrazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, phenyl, piperidinyl, morpholinyl, pyrrolidinyl, or piperazinyl;

(d) —C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl, or —O—C₀-C₄-alkyl-C₁-C₄-perfluoroalkyl;

(e) —O-aryl, or —O—C₁-C₄-alkyl-aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C; (f) CN, N(R^a)(R^b), NO₂, F, Cl, Br, I, —OR^a, —SR^a, —OCON(R^a)(R^b), —OSO₂N(R^a)(R^b), COOR^b, CON(R^a)(R^b), —N(R^a)CON(R^a)(R^b), —N(R^a)SO₂N(R^a)(R^b), C(OR^b)R^a, —C(OR^a)CF₃, C(NHR^a)CF₃, C(═O)R^a, C(═O)CF₃, —SOCH₃, —SO₂CH₃, —NHSO₂(C_1-6-alkyl), —NHSO₂-aryl, SO₂N(R^a)(R^b), —CH₂OSO₂N(R^a)(R^b), SO₂N(R^b)—OR^a, —C(═NH)NH₂, —CR_a═N—OR_a, CH═CH or aryl, wherein aryl is phenyl, pyridyl, pyrimidinyl, furyl, thienyl, pyrrolyl, triazolyl, pyrazolyl, thiazolyl, isoxazolyl, oxazolyl, or oxadiazolyl, any aryl of which is optionally substituted with 1-3 substituents selected from i) F, Cl, Br, I, ii) —CN, iii) —NO₂, iv) —C(═O)(R^a), v) —OR^a, vi) —NR^aR^b, vii) —C_0-4alkyl-CO—OR^a, viii) —(C_0-4alkyl)-NH—CO—OR^a, ix) —(C_0-4alkyl)-CO—N(R^a)(R^b), x) —S(O)_0-2R^a, xi) —SO₂N(R^a)(R^b), xii) —NR^aSO₂R^a, xiii) —C_1-10alkyl, and xiv) —C_1-10alkyl, wherein one or more of the alkyl carbons can be replaced by a —NR^a—, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(R^a)—, —N(R^a)—C(O)—, —N(R^a)—C(O)—N(R^a)—, —C(O)—, —CH(OH)—, —C═C—, or —C≡C; or when R⁶ and R⁷ are present on adjacent carbon atoms, R⁶ and R⁷, together with the ring to which they are attached, may form a bicyclic aromatic ring selected from naphthyl, indolyl, quinolinyl, isoquinolinyl, quinoxalinyl, benzofuryl, benzothienyl, benzoxazolyl, benzothiazolyl, and benzimidazolyl, any aromatic ring of which is optionally substituted with 1-4 independent substituents selected from i) halogen, ii) —CN, iii) —NO₂, iv) —CHO, v) —O—C_1-4alkyl, vi) —N(C _0-4alkyl)(C_0-4alkyl), vii) —C_0-4alkyl-CO—O(C_0-4alkyl), viii) —(C_0-4alkyl)-NH—CO—O(C_0-4alkyl), ix) —(C_0-4alkyl)-CO—N(C_0-4alkyl)(C_0-4alkyl), x) —S(C_0-4alkyl), xi) —S(O)(C_1-4alkyl), xii) —SO₂(C_0-4alkyl), xiii) —SO₂N(C_0-4alkyl)(C_0-4alkyl), xiv) —NHSO₂(C_0-4alkyl)(C_0-4alkyl), xv) —C_1-10alkyl and xvi) —C_1-10alkyl in which one or more of the carbons can be replaced by a —N(C_0-6alkyl)-, —O—, —S(O)_1-2—, —O—C(O)—, —C(O)—O—, —C(O)—N(C_0-6alkyl)-, —N(C_0-6alkyl)-C(O)—, —N(C_0-6alkyl)-C(O)—N(C_0-6alkyl)-, —C(O)—, —CH(OH), —C═C—, or —C≡C—; with the proviso that R¹, R³ and R⁶ are Not hydrogen at the same time.