Immunostimulating 6-aryl-5,6-dihydroimidazo[2,1-b]thiazole derivatives

An immunostimulating composition comprising an inert carrier and as active ingredient an effective immunostimulating amount of a compound of the formula:

• ##STR37## a pharmaceutically acceptable acid addition salt thereof or a stereochemically isomeric form thereof, wherein:
• Ar is phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, mercapto, C.sub.1-6 alkylthio, C.sub.1-6 alkyl, nitro, amino, mono- and di(C.sub.1-6 -alkyl)amino, C.sub.1-6 alkylcarbonylamino, arylcarbonylamino, C.sub.1-6 alkylsulfonylamino, trifluoromethyl, cyano, aminocarbonyl, mono- and di(C.sub.1-6 alkyl)aminocarbonyl, hydroxycarbonyl, C.sub.1-6 alkyloxycarbonyl, carboxaldehyde and hydroxymethyl;
• pyridinyl;
• thienyl;
• furanyl or furanyl substituted with C.sub.1-6 alkyl or halo;
• R.sup.1 is C.sub.3-10 alkyl, (C.sub.3-7 cycloalkyl)C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, aryl or (aryl)C.sub.1-6 alkyl;
• R.sup.2 is hydrogen, C.sub.1-20 alkyl, (C.sub.3-7 cycloalkyl)C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, aryl or (aryl)C.sub.1-6 alkyl;
• or R.sup.1 and R.sup.2 together may form a C.sub.3-6 alkandiyl radical;
• wherein in the foregoing each aryl independently is phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, C.sub.1-6 alkyl, nitro, amino, trifluoromethyl or cyano.

A method of treating humans and warm-blooded animals suffering from disorders or diseases wherein the immune system is impaired, said method comprising the systemic administration to said humans and warm-blooded animals of an effective immunostimulating amount of a compound of the formula:

• ##STR38## a pharmaceutically acceptable acid addition salt thereof or a stereochemically isomeric form thereof, wherein:
• Ar is phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, mercapto, C.sub.1-6 alkylthio, C.sub.1-6 alkyl, nitro, amino, mono- and di(C.sub.1-6 alkyl)amino, C.sub.1-6 alkylcarbonylamino, arylcarbonylamino, C.sub.1-6 alkylsulfonylamino, trifluoromethyl, cyano, aminocarbonyl, mono- and di(C.sub.1-6 alkyl)aminocarbonyl, hydroxycarbonyl, C.sub.1-6 alkyloxycarbonyl, carboxaldehyde and hydroxymethyl;
• pyridinyl;
• thienyl;
• furanyl or furanyl substituted with C.sub.1-6 alkyl or halo;
• R.sup.1 and R.sup.2 each independently are C.sub.1-20 alkyl, (C.sub.3-7 cycloalkyl)C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, aryl or (aryl)C.sub.1-6 alkyl;
• and one of R.sup.1 and R.sup.2 may also be hydrogen;
• or R.sup.1 and R.sup.2 together may form a C.sub.3-6 alkandiyl radical;
• wherein in the foregoing each aryl independently is phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, C.sub.1-6 alkyl, nitro, amino, trifluoromethyl or cyano.