Methods of synthesizing 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) and structural analogs thereof. The methods include condensation reactions or condensation and oxidation reactions to form the thiazoline or thiazole moiety of ITE or its structural analogs.

Disclosed is an aryl hydrocarbon receptor modulator of formula (I), and a pharmaceutically acceptable salt thereof, wherein

##STR00001##

R is H, CN, CH.sub.2(OH)R.sub.0, C.sub.mH.sub.2m+1, C.sub.nH.sub.2n1, C.sub.nH.sub.2n3,

##STR00002##

two R.sub.a are independently H or two R.sub.a together form =0 or NW.sub.3R.sub.1; A is a C.sub.6 to C.sub.10 aromatic ring unsubstituted or substituted with 1 to 3 R, or a C.sub.2-C.sub.10 heteroaromatic ring interrupted by 1 to 5 heteroatoms selected from N, 0, and S or a 4 to 7 membered nonaromatic heterocyclic ring containing CN and interrupted by 1 to 3 heteroatoms selected from N, 0, and S, with either one unsubstituted or substituted with 1 to 3 R; Q is R, or is a C.sub.6 to C.sub.10 aromatic ring or a C.sub.2 to C.sub.10 heteroaromatic ring unsubstituted or substituted with 1 to 3 R and interrupted by 1 to 5 heteroatoms selected from N, 0, and S; and R is R.sub.C which is C-attached or R.sub.N which is N-attached. The compounds of formula (I) of the present invention can regulate AhR activity, and can be used to inhibit the growth of cancer cells and inhibit the metastasis and invasion of tumor cells.

Methods of synthesizing 2(1H-indole-3-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) and structural analogs thereof. The methods include condensation reactions or condensation and oxidation reactions to form the thiazoline or thiazole moiety of ITE or its structural analogs.

A continuous flow process for the preparation of one or more esters of lactic acid and 2-hydroxy-3-butenoic acid or -hydroxy methionine analogs from a sugar in the presence of a solid Lewis acid catalyst and a solvent comprising an organic solvent and water. The invention provides a means for stabilizing a Lewis acid catalyst for use in a continuous reaction process wherein the water is present in an amount of up to or equal to 10 vol. % of the organic solvent.

Methods of synthesizing 2-(1H-indole-3-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) and structural analogs thereof. The methods include condensation reactions or condensation and oxidation reactions to form the thiazoline or thiazole moiety of ITE or its structural analogs.