5-Ht2b Receptor Antagonists

1 - 91 . (canceled)

92 . A compound of formula I:

or a salt, solvate and chemically protected form thereof, wherein:

X is O or NH;

R 2 and R 3 are independently selected from the group consisting of H, and optionally substituted C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl-C 1-4 alkyl, and phenyl-C 1-4 alkyl;

R 1 is an optionally substituted C 9-14 aryl group or an optionally substituted bi-C 5-7 aryl group;

R N1 and R N2 are either:

(i) independently selected from H, R, R′, SO 2 R, C(═O)R, (CH 2 ) n NR N3 R N4 , where n is from 1 to 4 and R N3 and R N4 are independently selected from H and R, where R is optionally substituted C 1-4 alkyl, and R′ is optionally substituted phenyl-C 1-4 alkyl, or

(ii) together with the nitrogen atom to which they are attached, form an optionally substituted C 5-7 heterocyclic group;

with the provisos that when R N1 , R N2 and R 2 are H, R 3 is methyl, and X is NH, then R 1 is not:

93 . The compound according to claim 92 , wherein R N1 and R N2 are both H.

94 . The compound according to claim 92 , wherein R 2 is H.

95 . The compound according to claim 92 , wherein R 1 is an optionally substituted biphenyl group.

96 . A compound of formula II:

or a salt, solvate and chemically protected form thereof, wherein:

R 5 is selected from the group consisting of H, and optionally substituted C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl-C 1-4 alkyl, and phenyl-C 1-4 alkyl;

R 4 is an optionally substituted C 9-14 aryl group or an optionally substituted bi-C 5-7 aryl group;

R N5 and R N6 are either:

(i) independently selected from H, R, R′, SO 2 R, C(═O)R, (CH 2 ) n NR N7 R N8 , where n is from 1 to 4 and R N7 and R N8 are independently selected from H and R, where R is optionally substituted C 1-4 alkyl, and R′ is optionally substituted phenyl-C 1-4 alkyl, or

(ii) together with the nitrogen atom to which they are attached, form an optionally substituted C 5-7 heterocyclic group;

with the provisos that when R N5 , R N6 and R 5 are H, R 4 is not unsubstituted 1- or 2-naphthyl or unsubstituted 4-phenyl-phenyl

and that when R N6 and R 5 are H, and R N5 is acetyl then R 4 is not unsubstituted 2-naphthyl.

97 . The compound according to claim 96 , wherein at least one of R N5 and R N6 is H, and the other is selected from H and C(═O)Me.

98 . The compound according to claim 96 , wherein R 5 is H.

99 . The compound according to claim 96 , wherein R 4 is an optionally substituted 3- or 4-C 5-6 aryl-C 5-6 aryl group.

100 . A compound of formula IIIa or IIIb:

or a salt, solvate and chemically protected form thereof,

wherein:

R 8 is selected from the group consisting of H, and optionally substituted C 1-6 alkyl, C 3-7 cycloalkyl, C 3-7 cycloalkyl-C 1-4 alkyl, and phenyl-C 1-4 alkyl;

R 7 is an optionally substituted bi-C 5-7 aryl group;

R N9 and R N10 are either:

(i) independently selected from H, R, R′, SO 2 R, C(═O)R, (CH 2 ) n NR N11 R N12 , where n is from 1 to 4 and R N11 and R N12 are independently selected from H and R, where R is optionally substituted C 1-4 alkyl, and R′ is optionally substituted phenyl-C 1-4 alkyl, or

(ii) together with the nitrogen atom to which they are attached, form an optionally substituted C 5-7 heterocyclic group;

with the proviso that in formula IIIb, when R N9 , R N10 and R 8 are H, R 7 is not 4-phenyl-phenyl.

101 . The compound according to claim 100 , wherein R 8 is selected from H and optionally substituted C 1-6 alkyl.

102 . The compound according to claim 100 , wherein R N9 and R N10 are independently selected from H and R.

103 . The compound according to claim 102 , wherein R 7 is an optionally substituted bi-phenyl group.

104 . A compound of formula IVa or IVb:

or a salt, solvate and chemically protected form thereof, wherein:

R 10 is selected from the group consisting of H and optionally substituted C 1-6 alkyl;

R 9 is an optionally substituted C 9-14 aryl group or an optionally substituted bi-C 5-7 aryl group;

R N13 and R N14 are either:

(i) independently selected from H, R, R′, SO 2 R, C(═O)R, (CH 2 ) n NR N15 R N16 , where n is from 1 to 4 and R N15 and R N16 are independently selected from H and R, where R is optionally substituted C 1-4 alkyl, and R′ is optionally substituted phenyl-C 1-4 alkyl, or

(ii) together with the nitrogen atom to which they are attached, form an optionally substituted C 5-7 heterocyclic group,

with the proviso that when R 10 , R N13 and R N14 are H, R 9 is not an unsubstituted naphthyl group.

105 . The compound according to claim 104 , wherein R 10 is selected from H and optionally substituted C 1-6 alkyl.

106 . The compound according to claim 104 , wherein R N13 and R N14 are independently selected from H and R.

107 . The compound according to claim 104 , wherein R 9 is an optionally substituted bi-phenyl group.

108 . A method of treating a condition which can be alleviated by antagonism of a 5-HT 2B receptor, which method comprises administering to a patient in need of treatment an effective amount of a compound according to claim 92 .

109 . A method of treating a condition which can be alleviated by antagonism of a 5-HT 2B receptor, which method comprises administering to a patient in need of treatment an effective amount of a compound according to claim 96 .

110 . A method of treating a condition which can be alleviated by antagonism of a 5-HT 2B receptor, which method comprises administering to a patient in need of treatment an effective amount of a compound according to claim 100 .

111 . A method of treating a condition which can be alleviated by antagonism of a 5-HT 2B receptor, which method comprises administering to a patient in need of treatment an effective amount of a compound according to claim 104 .