A series of 2-substituted benzothiazoles have been synthesized by the condensation of 2-aminothiophenol with aldehydes (RCHO: R = Alkyl, Aryl, Heteroaryl, 2-Arylformyl) in the presence of a catalytic amount of cetyltrimethyl ammonium bromide (CTAB) "on water" by a one-pot procedure without additional organic solvents and oxidants. Thereinto, 2-alkylbenzothiazoles were synthesized in high yields and 2-arylformylbenzothiazoles were obtained from the condensation of 2-aminothiophenol with arylformyl aldehydes for the first time using the present protocol.