Compounds that inhibit (block) bitter taste in composition and methods of making same

A compound of the formula B:

• or a salt or N-oxide thereof,
• wherein Alk is an alkyl group;
• M1 is N or CR49, wherein R49 is H or substituted or unsubstituted alkyl;
• M2 is N or CR50, wherein R50 is H or substituted or unsubstituted alkyl;
• R47 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo;
• and
• R48 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo.

A compound of the formula C:

• or a salt or N-oxide thereof,
• wherein Alk is an alkyl group;
• M1 is N or CR49, wherein R49 is H or substituted or unsubstituted alkyl;
• M2 is N or CR50, wherein R50 is H or substituted or unsubstituted alkyl;
• R47 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo;
• and
• R48 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo.

A method of making a compound of the formula A:

• or a salt or N-oxide thereof,
• wherein Alk is an alkyl group;
• R51 and R52 are, the same or different independently one from the other, H, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl alkyl, substituted or unsubstituted heterocycloalkylalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylamidoalkyl, substituted or unsubstituted arylalkylamidoalkyl, substituted or unsubstituted heteroarylamidoalkyl, substituted or unsubstituted heteroarylalkylamidoalkyl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkoxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, haloalkyl, or R51 and R52, together with the carbon atom to which they are attached, form a substituted or unsubstituted alkenyl group;
• M1 is N or CR49, wherein R49 is H or substituted or unsubstituted alkyl;
• M2 is N or CR50, wherein R50 is H or substituted or unsubstituted alkyl;
• R38 is H, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl alkyl, substituted or unsubstituted heterocycloalkylalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylamidoalkyl, substituted or unsubstituted heteroarylamidoalkyl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkoxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, or haloalkyl;
• R47 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo;
• and
• R48 is H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, or halo;
• wherein the method comprises reacting a compound of the formula B:
• or a salt or N-oxide thereof;
• wherein R47, R48, Alk, M1, and M2 are defined above;
• with a compound of formula D:
• or a salt thereof;
• wherein J3 is a leaving group and R38, R51, and R52 are defined above, to give a compound of formula A or a salt or N-oxide thereof.