ofN-acylbenzotriazoles Ic, f, g illustrate the preparation of acyl derivatives not easily

available by other methods.

 6.4 Experimental Section

 Melting points are uncorrected. H NMR (300 MHz) and 13C NMR (75 MHz)

spectra were recorded in CDC13 (with TMS for 1H and chloroform-d for 13C as the

internal reference) unless specified otherwise.

6.4.1 General Procedure for the Preparation of N-Acylbenzotriazoles 6.1a-g.

 A mixture of aromatic or heteroaromatic acid (20 mmol), 1-

(methylsulfonyl)benzotriazole[00JOC8210] (20 mmol) and triethylamine (4.0 mL, 28

mmol) was dissolved in THF (120 mL) and the solution was heated under reflux

overnight (except for 6.1f which required heating at 40 C for 2 days). The solvent was

evaporated under reduced pressure and the residue was dissolved in chloroform. Aqueous

work-up gave the crude product that was recrystallized to give pure N-acylbenzotriazoles

6.1a-g.

 1H-1,2,3-Benzotriazol-l-yl(4-methylphenyl)methanone (6.1a): colorless prisms

(from ethanol); mp 123-124 C (Lit.[00JOC8210] mp 123-124 C); yield, 91%.

 1H-1,2,3-Benzotriazol-l-yl(4-nitrophenyl)methanone (6.1b): yellow needles

(from chloroform/ hexanes); mp 192-193 C (Lit.[00JOC8210] mp 193-194 C); yield,

81%.

 1H-1,2,3-Benzotriazol-l-yl[4-(diethylamino)phenyl]methanone (6.1c): yellow

needles (from ethanol/hexanes); mp 85-87 C (Lit.[00JOC8210] mp 86-87 C); yield,

87%.