Medium pore aluminophosphate-based molecular sieves like AlPO-41, CoAPO-41, CoAPSO-41 and MnAPSO-41 have been synthesised hydrothermally using dipropylamine as the organic template. These materials have been characterised by various physical methods including X-ray powder diffraction (XRD), thermogravimetric analyses (TGA), FT-IR, ESR and scanning electron microscope (SEM). All these materials are found to be crystalline and do not contain any detectable impure phases. The catalytic performance of these materials has been examined for ethylation of ethylbenzene with ethanol at 250, 300, 350, 400 and 450degreesC. Ethylbenzene conversion is observed to increase with increase in temperature with the maximum conversion at 400 C. The major product is 1,4-diethylbenzene whose selectivity decreases with increase in temperature over all the catalysts. High temperature is favourable for the formation of 1,3-diethylbenzene which is thermodynamically more stable than the other products. Influence of feed ratio on conversion and products selectivity is examined and the results are discussed in this paper. (C) 2002 Elsevier Science B.V. All rights reserved.