Heterocyclic derivatives
    2.
    发明授权

    公开(公告)号:US4410523A

    公开(公告)日:1983-10-18

    申请号:US199522

    申请日:1980-10-22

    CPC分类号: C07D249/14 Y10S514/927

    摘要: The invention provides compounds of the general formula (I) ##STR1## and physiologically acceptable salts, hydrates and bioprecursors thereof, in whichR.sub.1 and R.sub.2, which may be the same or different, each represent hydrogen, C.sub.1-10 alkyl, cycloalkyl, alkenyl, aralkyl, trifluoroalkyl, heteroaralkyl, or alkyl substituted by hydroxy, alkoxy, amino, alkylamino, dialkyamino or cycloalkyl, or R.sub.1 and R.sub.2 may together with the nitrogen atom to which they are attached form a 5 to 10 membered ring which may be saturated or may contain at least one double bond, may be unsubstituted or may be substituted by one or more C.sub.1-3 alkyl groups, or a hydroxy group and/or may contain another heteroatom selected from oxygen and sulphur;Alk represents a straight or branched alkylene chain of 1 to 6 carbon atoms and is attached to the cyclohexadiene ring at either the 4- or 5- position;X represents --CH.sub.2 or --O--;m represents 2, 3, 4 or 5 and when X is --O-- the chain (CH.sub.2).sub.m may be interrupted by an oxygen atom provided that there are at least two methylene groups between any two heteroatoms in the moiety --X(CH.sub.2).sub.m NH--;R.sub.3 represents hydrogen, alkyl, alkenyl, aralkyl, or C.sub.2-6 alkyl substituted by hydroxy or alkoxy; andR.sub.4 represents hydrogen, alkyl, alkenyl, aralkyl, hydroxyalkyl, acyloxyalkyl, alkoxyalkyl, aryloxyalkyl, aralkyloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, hydroxy or alkoxy or the group NR.sub.5 R.sub.6 whereR.sub.5 represents hydrogen, alkyl, alkyl substituted by hydroxy or C.sub.1-3 alkoxy, alkenyl, aralkyl or heteroaralkyl and R.sub.6 represents any of the groups defined for R.sub.5 or may represent the group COR.sub.7 where R.sub.7 represents hydrogen, alkyl, aryl, aralkyl, alkoxy, heteroaryl or monocyclic heteroaralkyl or R.sub.6 represents the group SO.sub.2 R.sub.8 where R.sub.8 represents alkyl or aryl, or R.sub.6 represents the group ##STR2## where Y is oxygen or sulphur and R.sub.9 represents hydrogen, alkyl, cycloalkyl, aryl or aralkyl,or R.sub.5 and R.sub.6 taken together may represent the group .dbd.CR.sub.10 R.sub.11 where R.sub.10 represents aryl or heteroaryl and R.sub.11 represents hydrogen or alkyl.The compounds show activity as selective histamine H.sub.2 -antagonists.

    Furan derivatives having selective action on histamine receptors
    3.
    发明授权
    Furan derivatives having selective action on histamine receptors 失效
    呋喃衍生物对组胺受体具有选择性作用

    公开(公告)号:US4255440A

    公开(公告)日:1981-03-10

    申请号:US951026

    申请日:1978-10-13

    摘要: Compounds of the general formula I: ##STR1## and physiologically acceptable salts thereof and N-oxides and hydrates, in which R.sub.1 and R.sub.2 which may be the same or different represent hydrogen, lower alkyl, cycloalkyl, lower alkenyl, aralkyl or lower alkyl interrupted by an oxygen atom or a group ##STR2## in which R.sub.4 represents hydrogen or lower alkyl or R.sub.1 and R.sub.2 may, together with the nitrogen atom to which they are attached, form a heterocyclic ring which may contain other heteroatoms selected from O and ##STR3## R.sub.3 is hydrogen, lower alkyl, lower alkenyl or alkoxyalkyl; X is --CH.sub.2 --, O-- or --S--;Y represents .dbd.S, .dbd.O, .dbd.NR.sub.5 or .dbd.CHR.sub.6 ;Alk denotes a straight or branched alkylene chain of 1 to 6 carbon atoms;R.sub.5 is H, nitro, cyano, lower alkyl, aryl, alkylsulphonyl, or arylsulphonyl;R.sub.6 represents nitro, arylsulphonyl or alkylsulphonyl;m is an integer from 2 to 4; andn is 1 or 2; or when X is --S-- or --CH.sub.2 --, n is zero, 1 or 2.These compounds have H.sub.2 -antagonist activity. Intermediates in the production thereof are also provided.

    摘要翻译: 通式I的化合物及其生理上可接受的盐和N-氧化物和水合物,其中可以相同或不同的R 1和R 2表示氢,低级烷基,环烷基,低级烯基,芳烷基或 被氧原子间隔的低级烷基或其中R 4表示氢或低级烷基或R 1和R 2的基团可以与它们所连接的氮原子一起形成杂环,该杂环可以含有选自O 且R 3为氢,低级烷基,低级烯基或烷氧基烷基; X是-CH 2 - ,O-或-S-; Y表示= S,= O,= NR5或= CHR6; Alk表示1〜6个碳原子的直链或支链亚烷基链; R5是H,硝基,氰基,低级烷基,芳基,烷基磺酰基或芳基磺酰基; R6表示硝基,芳基磺酰基或烷基磺酰基; m为2〜4的整数; n为1或2; 或当X为-S-或-CH 2 - 时,n为0,1或2.这些化合物具有H 2 - 拮抗剂活性。 还提供了其生产中的中间体。

    1,2,4-Triazole-3,5-diamine derivatives
    4.
    发明授权
    1,2,4-Triazole-3,5-diamine derivatives 失效
    1,2,4-三唑-3,5-二胺衍生物

    公开(公告)号:US4318913A

    公开(公告)日:1982-03-09

    申请号:US33508

    申请日:1979-04-26

    摘要: The invention relates to compounds of the formula (I) ##STR1## and physiologically acceptable salts, hydrates and bioprecursors thereof, in whichR.sub.1 and R.sub.2 represent hydrogen, an aliphatic or cycloaliphatic group, or R.sub.1 and R.sub.2 together with the nitrogen atom form a 5 to 10 membered heterocyclic ring:Alk represents a straight or branched alkylene chain;Q represents furan, thiophen or benzene ring which is incorporated into the rest of the molecule;X represents --CH.sub.2 --, ##STR2## --O-- or --S-- whereR.sub.6 represents hydrogen or methyl;n represents zero, 1 or 2;m represents 2, 3 or 4;R.sub.3 represents hydrogen, a substituted or unsubstituted aliphatic or aryl group and;R.sub.4 and R.sub.5, which may be the same or different, each represent hydrogen, a substituted or unsubstituted aliphatic, aryl, or together with the nitrogen atom form a heterocyclic group.

    摘要翻译: 本发明涉及式(I)化合物及其生理学上可接受的盐,水合物和生物前体,其中R 1和R 2表示氢,脂族或脂环族基团,或R 1和R 2与氮原子一起 形成5至10元杂环:Alk表示直链或支链亚烷基链; Q表示呋喃,噻吩或苯环,其结合到分子的其余部分中; X表示-CH 2 - , -O-或-S-,其中R 6表示氢或甲基; n表示0,1或2; m表示2,3或4; R 3表示氢,取代或未取代的脂族或芳基, R 4和R 5可以相同或不同,各自表示氢,取代或未取代的脂族基,芳基或与氮原子一起形成杂环基。

    Aminoalkyl furan derivatives
    5.
    发明授权
    Aminoalkyl furan derivatives 失效
    氨基烷基呋喃衍生物

    公开(公告)号:US4128658A

    公开(公告)日:1978-12-05

    申请号:US818762

    申请日:1977-07-25

    摘要: Compounds of the general formula I: ##STR1## and physiologically acceptable salts thereof and N-oxides and hydrates, in which R.sub.1 and R.sub.2 which may be the same or different represent hydrogen, lower alkyl, cycloalkyl, lower alkenyl, aralkyl or lower alkyl interrupted by an oxygen atom or a group ##STR2## in which R.sub.4 represents hydrogen or lower alkyl or R.sub.1 and R.sub.2 may, together with the nitrogen atom to which they are attached, form a heterocyclic ring which may contain other heteroatoms selected from O and ##STR3## R.sub.3 is hydrogen, lower alkyl, lower alkenyl or alkoxyalkyl; X is --CH.sub.2 --, O or S;Y represents .dbd. S, .dbd. O, .dbd. NR.sub.5 or .dbd. CHR.sub.6 ;Alk denotes a straight or branched alkylene chain of 1 to 6 carbon atoms;R.sub.5 is H, nitro, cyano, lower alkyl, aryl, alkylsulphonyl, or arylsulphonyl;R.sub.6 represents nitro, arylsulphonyl or alkylsulphonyl;M is an integer from 2 to 4; andN is 1 or 2; or when X .dbd. S, or --CH.sub.2 --, n is zero, 1 or 2.These compounds have H.sub.2 -antagonist activity. Intermediates in the production thereof are also provided.

    摘要翻译: 通式I的化合物及其生理上可接受的盐和N-氧化物和水合物,其中可以相同或不同的R 1和R 2表示氢,低级烷基,环烷基,低级烯基,芳烷基或 被氧原子间隔的低级烷基或其中R 4表示氢或低级烷基或R 1和R 2的基团可以与它们所连接的氮原子一起形成杂环,该杂环可以含有选自O 且R 3为氢,低级烷基,低级烯基或烷氧基烷基; X是-CH 2 - ,O或S; Y表示= S,= O,= NR5或= CHR6; Alk表示1〜6个碳原子的直链或支链亚烷基链; R5是H,硝基,氰基,低级烷基,芳基,烷基磺酰基或芳基磺酰基; R6表示硝基,芳基磺酰基或烷基磺酰基; M是从2到4的整数; 和N是1或2; 或当X = S或-CH 2 - 时,n为0,1或2。

    1H-1,2,4-Triazole-3,5-diamine derivatives and use as selective histamine
H.sub.2 -antagonists

    公开(公告)号:US4442110A

    公开(公告)日:1984-04-10

    申请号:US324440

    申请日:1981-11-24

    摘要: The invention relates to compounds of the general formula (I) ##STR1## and physiologically acceptable salts, hydrates and bioprecursors thereof, in whichR.sub.1 and R.sub.2, which may be the same or different, each represent hydrogen, C.sub.1-10 alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, trifluoroalkyl or alkyl substituted by hydroxy, alkoxy, amino, alkylamino, dialkylamino or cycloalkyl, or R.sub.1 and R.sub.2 may together with the nitrogen atom to which they are attached form a 5 to 10 membered alicyclic heterocyclic ring which may be saturated or may contain at least one double bond, may be unsubstituted or may be substituted by one or more C.sub.1-3 alkyl groups or a hydroxy group and/or may contain another heteroatom;Alk represents a straight or branched alkylene chain of 1 to 6 carbon atoms;Q represents a furan or thiophen ring in which incorporation into the rest of the molecule is through bonds at the 2- and 5-positions, the furan ring optionally bearing a further substituent R.sub.7 adjacent to the group R.sub.1 R.sub.2 N-Alk-, or Q represents a benzene ring in which incorporation into the rest of the molecule is through bonds at the 1- and 3- or 1- and 4- positions;R.sub.7 represents halogen or C.sub.1-4 alkyl which may be substituted by hydroxy or C.sub.1-4 alkoxy;X represents --CH.sub.2 --, ##STR2## --O-- or --S-- whereR.sub.6 represents hydrogen or methyl;n represents zero, 1 or 2;m represents 2, 3 or 4;R.sub.3 represents hydrogen, alkyl, alkenyl, aralkyl, hydroxyalkyl having at least two carbon atoms, alkoxyalkyl or aryl; andR.sub.4 and R.sub.5, which may be the same or different, each represent hydrogen, alkyl, alkyl substituted by hydroxy or C.sub.1-3 alkoxy, alkenyl, aralkyl or heteroaralkyl or R.sub.4 and R.sub.5 may together with the nitrogen atom to which they are attached form a 5 to 7-membered saturated heterocyclic ring which may contain another heteroatom, or the group ##STR3## or R.sub.4 and R.sub.5 taken together may represent the group .dbd.CR.sub.8 R.sub.9 where R.sub.8 represents aryl or heteroaryl and R.sub.9 represents hydrogen or alkyl.Preferably when X represents an oxygen atom or ##STR4## and n is zero, then Q only represents a benzene ring. The compounds of formula (I) show pharmacological activity as selective histamine H.sub.2 -antagonists.

    Substituted furan compounds and pharmaceutical compositions containing
them
    7.
    发明授权
    Substituted furan compounds and pharmaceutical compositions containing them 失效
    取代的呋喃化合物和含有它们的药物组合物

    公开(公告)号:US4288443A

    公开(公告)日:1981-09-08

    申请号:US124115

    申请日:1980-02-25

    摘要: The invention relates to compounds of the general formula ##STR1## and physiologically acceptable salts and N-oxides, hydrates and bioprecursors thereof, in which R.sub.1 and R.sub.2 which may be the same or different each represent hydrogen, C.sub.1-8 alkyl, C.sub.4-8 cycloalkyl, C.sub.3-6 alkenyl, aralkyl with 1 to 4 carbon atoms in the alkyl residue or C.sub.1-8 alkyl interrupted by an oxygen atom or a group ##STR2## in which R.sub.5 represents hydrogen or C.sub.1-8 alkyl, or R.sub.1 and R.sub.2 may together with the nitrogen atom to which they are attached, form a saturated monocyclic 5 to 7 membered heterocyclic ring which may additionally contain the heterofunction O or ##STR3## R.sub.3 represents straight or branched chain C.sub.1-8 alkyl, alkoxyalkyl with 1 to 8 carbon atoms in each alkyl residue, C.sub.1-8 hydroxyalkyl, C.sub.1-8 alkoxycarbonyl, alkyl thioalkyl with 1 to 8 carbon atoms in each alkyl residue, halogen or aryl;R.sub.4 represents hydrogen, C.sub.1-8 alkyl, C.sub.3-6 alkenyl or alkoxyalkyl with 1 to 8 carbon atoms in each alkyl residue;X represents --O-- or --S--;Y represents .dbd.S, .dbd.O, .dbd.NR.sub.6 or .dbd.CHNO.sub.2 where R.sub.6 represents hydrogen, nitro, cyano, C.sub.1-8 alkyl, aryl, C.sub.1-8 alkylsulphonyl or arylsulphonyl;m represents an integer from 2 to 4 inclusive; andn represents an integer which is 1 or 2, or additionally when X is --S-- n may also be zero.The invention also relates to processes for the production of such compounds, pharmaceutical compositions containing them and certain novel intermediates used in their production, i.e. amines of the formula ##STR4## and alcohols of the formula ##STR5## The compounds of formula (I) show pharmacological activity as selective histamine H.sub.2 -antagonists.

    摘要翻译: 本发明涉及通式为(I)的化合物及其生理上可接受的盐和N-氧化物,水合物和生物前体,其中可以相同或不同的R 1和R 2各自表示氢,C 1-8烷基, C4-8环烷基,C3-6烯基,在烷基中具有1至4个碳原子的芳烷基或被氧原子间断的C1-8烷基或其中R5表示氢或C1-8烷基的基团,或R1 并且R 2可以与它们所连接的氮原子一起形成饱和的单环5至7元杂环,其可另外含有杂官能O,或者R 3表示直链或支链C 1-8烷基,烷氧基烷基与1至 每个烷基残基中的8个碳原子,C 1-8羟基烷基,C 1-8烷氧基羰基,每个烷基残基中具有1至8个碳原子的烷基硫代烷基,卤素或芳基; R4表示氢,C1-8烷基,C3-6烯基或每个烷基残基具有1至8个碳原子的烷氧基烷基; X表示-O-或-S-; Y表示= S,= O,= NR6或= CHNO2,其中R6表示氢,硝基,氰基,C1-8烷基,芳基,C1-8烷基磺酰基或芳基磺酰基; m表示2〜4的整数, 并且n表示1或2的整数,或者当X是-S-n时也可以为零。 本发明还涉及生产这种化合物的方法,含有它们的药物组合物和它们生产中使用的某些新型中间体,即式(III)的胺和式的醇(VIII)。化合物 式(I)表示作为选择性组胺H2拮抗剂的药理学活性。

    Heterocyclic derivatives, processes for the use thereof and
pharmaceutical compositions containing them
    8.
    发明授权
    Heterocyclic derivatives, processes for the use thereof and pharmaceutical compositions containing them 失效
    杂环衍生物,其使用方法和含有它们的药物组合物

    公开(公告)号:US4777179A

    公开(公告)日:1988-10-11

    申请号:US789578

    申请日:1985-10-21

    摘要: The invention provides compounds of the general formula ##STR1## and physiologically acceptable salts and hydrates thereof, in which one of R.sub.1 and R.sub.2 represents hydrogen, halogen or a C.sub.1-4 alkyl group which may be optionally substituted by hydroxy or C.sub.1-4 alkoxy, and the other represents the group R.sub.4 R.sub.5 NAlk-- in which Alk represents a straight or branched alkylene chain of 1 to 6 carbon atoms;R.sub.3, which may be in either the 2 or 3-position, represents the ##STR2## where X represents --CH.sub.2 --, --O-- or --S--; n represents zero, 1 or 2;m represents 2, 3 or 4; andR.sub.7 represents hydrogen, alkyl, alkenyl, aralkyl, or C.sub.2-6 alkyl substituted by hydroxy or alkoxy; andR.sub.8 represents hydrogen, alkyl, alkenyl, aralkyl, hydroxyalkyl, acyloxyalkyl, alkoxyalkyl, aryloxyalkyl, aralkyloxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, hydroxy or alkoxy, or the group NR.sub.10 R.sub.11 ; with the provisos thatwhere R.sub.2 represents the group R.sub.4 R.sub.5 Nalk then R.sub.3 is in the 2-position;where R.sub.2 represents hydrogen then R.sub.3 is in the 3-position; andwhere R.sub.2 represents halogen or C.sub.1-4 alkyl optionally substituted by hydroxy or C.sub.1-4 alkoxy, and R.sub.3 is in the 2-position, then R.sub.8 cannot represent amino C.sub.1-6 alkyl, C.sub.1-6 alkylamino C.sub.1-6 alkyl, di-C.sub.1-6 alkylamino C.sub.1-6 alkyl or a group NR.sub.10 R.sub.11.The compounds of formula (I) show pharmacological activity as selective histamine H.sub.2 -antagonists.

    摘要翻译: 本发明提供了通式(I)的化合物及其生理上可接受的盐和水合物,其中R 1和R 2中的一个表示氢,卤素或C 1-4烷基,其可任选被羟基或C1- 4烷氧基,另一个表示R4R5NAlk-基团,其中Alk表示1至6个碳原子的直链或支链亚烷基链; 可以在2或3位的R3表示其中X表示-CH 2 - , - O-或-S-的。 n表示0,1或2; m表示2,3或4; 并且R 7表示氢,烷基,烯基,芳烷基或被羟基或烷氧基取代的C 2-6烷基; 芳基烷氧基烷基,芳氧基烷基,芳烷氧基烷基,氨基烷基,烷基氨基烷基,二烷基氨基烷基,羟基或烷氧基,或基团NR10R11; R10代表氢,烷基,烯基,芳烷基, 条件是其中R2表示基团R4R5Nalk,则R3为2-位; 其中R2表示氢,R3表示3-位; 并且其中R 2表示卤素或任选被羟基或C 1-4烷氧基取代的C 1-4烷基,且R 3在2-位,那么R 8不能代表氨基C 1-6烷基,C 1-6烷基氨基C 1-6烷基, C 1-6烷基氨基C 1-6烷基或基团NR 10 R 11。 式(I)化合物显示作为选择性组胺H2拮抗剂的药理活性。

    Pyrimidone derivatives
    9.
    发明授权
    Pyrimidone derivatives 失效
    嘧啶衍生物

    公开(公告)号:US4524071A

    公开(公告)日:1985-06-18

    申请号:US58256

    申请日:1979-07-17

    摘要: Compounds of the formula (I) ##STR1## in which R.sub.1 and R.sub.2 each may represent hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, or alkyl, substituted by hydroxy, C.sub.1-3 alkoxy, amino, C.sub.1-3 alkylamino or di-C.sub.1-3 alkylamino or R.sub.1 and R.sub.2 together with the nitrogen atom to which they are attached form an alicyclic heterocyclic ring which may be unsubstituted or may be substituted by one or more C.sub.1-3 alkyl groups or a hydroxy group and/or may contain another heteroatom are described.Alk is a straight lower alkylene chain,Q is a furan or thiophen ring, the furan ring optionally bearing a further substituent R.sub.5 adjacent to the group R.sub.1 R.sub.2 NAlk-- or Q represents a benzene ring.R.sub.5 represents halogen or C.sub.1-3 alkyl which may be substituted by a hydroxy or C.sub.1-3 alkoxy group;X represents --CH.sub.2 --, --O-- or --S--;n represents zero or 1;m represents 2, 3 or 4;Y represents .dbd.O or .dbd.S;R.sub.3 represents hydrogen in which case R.sub.4 represents methyl or R.sub.3 represents --(CH.sub.2).sub.p V(CH.sub.2).sub.q Ar, phenyl, or alkyl in which case R.sub.4 represents hydrogen;V represents --CH.sub.2 --, --O--, or --S--;p represents zero, 1, 2 or 3;q represents zero, 1, 2 or 3;the sum of p+q being 3 or less;Ar represents an aromatic carbocyclic or heterocyclic ring being optionally substituted by at least one C.sub.1-3 alkyl, C.sub.1-3 alkoxy C.sub.1-3 alkyl, hydroxy, C.sub.1-3 alkoxy, methylenedioxy, halogen, trifluoromethyl or di-C.sub.1-3 alkylamino group;except that when n is zero and X is oxygen then Q represents a benzene or thiophen ring. The compounds of formula (I) have pharmacological activity as selective histamine H.sub.2 -antagonists.

    摘要翻译: 式(I)的化合物其中R 1和R 2各自可以表示被羟基,C 1-3烷氧基,氨基,C 1-3取代的氢,烷基,环烷基,烯基,炔基,芳烷基或烷基 烷基氨基或二-C 1-3烷基氨基或R 1和R 2与它们所连接的氮原子一起形成脂环族杂环,其可以是未取代的或可以被一个或多个C 1-3烷基或羟基和/ 或可以含有另外的杂原子。 Al是直链亚烷基链,Q是呋喃或噻吩环,呋喃环任选带有与R1R2NAlk-基团相邻的另外的取代基R5,或Q表示苯环。 R5表示可被羟基或C1-3烷氧基取代的卤素或C1-3烷基; X表示-CH 2 - , - O-或-S-; n表示0或1; m表示2,3或4; Y表示= O或= S; R 3表示氢,在这种情况下,R 4表示甲基或R 3表示 - (CH 2)p V(CH 2)qAr,苯基或烷基,在这种情况下,R 4表示氢; V表示-CH 2 - , - O-或-S-; p代表零,1,2或3; q表示零,1,2或3; p + q的和为3以下; Ar表示任选被至少一个C 1-3烷基,C 1-3烷氧基C 1-3烷基,羟基,C 1-3烷氧基,亚甲二氧基,卤素,三氟甲基或二-C 1-3烷基氨基取代的芳族碳环或杂环; 除了当n为0且X为氧时,Q表示苯或噻吩环。 式(I)化合物具有作为选择性组胺H2拮抗剂的药理学活性。

    Triazole acylamines, pharmaceutical compositions thereof and method of
use thereof

    公开(公告)号:US4323566A

    公开(公告)日:1982-04-06

    申请号:US125847

    申请日:1980-02-29

    摘要: The invention relates to compounds of the general formula (I) ##STR1## and physiologically acceptable salts, hydrates and bioprecursors thereof, in whichR.sub.1 and R.sub.2, which may be the same of different, each represent hydrogen, C.sub.1 alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, trifluoroalkyl, or alkyl substituted by hydroxy, alkoxy, amino alkylamino dialkylamino or cycloalkyl or R.sub.1 and R.sub.2 may together with the nitrogen atom to which they are attached form a 5 to 10 membered ring which may be saturated or may contain at least one double bond, may be unsubstituted or may be substituted by one or more C.sub.1-3 alkyl groups or a hydroxy group and/or may contain another heteroatom which is oxygen or sulphur;Alk represents a straight or branched alkylene chain of 1 to 6 carbon atoms,Q represents a furan or thiophene ring in which incorporation into the rest of the molecule is through bonds at the 2- and 5- positions, the furan ring optionally bearing a further substituent R.sub.6 adjacent to the group R.sub.1 R.sub.2 N-Alk, or Q represents a benzene ring in which incorporation into the rest of the molecule is through bonds at the 1- and 3- or 1- and 4- positions;R.sub.6 represents halogen or C.sub.1-4 alkyl which may be substituted by hydroxy or C.sub.1-4 alkoxy;x represents --CH.sub.2 --, --O--, --S--or ##STR2## where R.sub.5 represents hydrogen or methyl; n represents zero, 1 or 2;m represents 2, 3 or 4;R.sub.3 represents hydrogen, alkyl, alkenyl, aralkyl, hydroxyalkyl with at least two carbon atoms, alkoxyalkyl, or aryl, andR.sub.4 represents hydrogen, alkyl, alkenyl or aralkyl and R.sub.7 represents the group COR.sub.8 where R.sub.8 represents hydrogen, alkyl, aryl, aralkyl, alkoxy, heteroaryl or monocyclic heteroarylalkyl or R.sub.7 represents the group SO.sub.2 R.sub.9 where R.sub.9 represents alkyl or aryl, or R.sub.7 represents the group ##STR3## where Y is oxygen or sulphur and R.sub.10 represents hydrogen, alkyl, cycloalkyl, aryl or aralkyl.The compounds of formula (I) show pharmacological activity as selective histamine H.sub.2 - antagonists.