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Pictet-Spengler reaction with p-nitrobenzaldehyde was shortened from 48 h [1] to 3 h byperforming the reaction under microwave irradiation in a 1% TFA solution of 1,2-dichloroethane, instead of toluene. The cis relative stereochemistry of 10 was assignedbased on previous results [1]. Sodium methoxide mediated cleavage from the TAP supportoccurred with concomitant dehydrogenation at positions 4 and 5 of the diazepinone ring,leading to ester 11 in 17% overall yield after isolation by chromatography on silica gel.Scheme 1. Synthesis of pyrrolo[3,2-e][1,4]diazepin-2-one 11 on “Merrifield TAP” 2.Effective synthesis of pyrrolodiazepinone 11 was achieved using “Merrifield TAP” 2 assoluble support. This strategy permited straightforward isolation of intermediates and directfollowing of reactions by TLC and HPLC-MS. Only one purification of the final ester bysilica gel column chromatography was performed after seven steps. Work is underway toimprove the cleavage step and to explore other supports for the combinatorial synthesis ofpyrrolo[3,2-e][1,4]diazepin-2-ones.AcknowledgmentsWe acknowledge financial support from NSERC, CIHR, CIHR-Team in GPCR allosteric regulation(CTiGAR), FQRNT. We thank Marie-Noelle Roy of Soluphase Inc. (Montreal, Canada) for fruitfuldiscussions.References1. Deaudelin, P., Lubell, W.D. Org. Lett. 10, 2841-2844 (2008).2. Iden, H.S., Lubell, W.D. Org. Lett. 8, 3425-3428 (2006).3. Poupon, J.C., Boezio, A.A., Charette, A.B. Angew. Chem., Int. Ed. 45, 1415-1420 (2006).4. Roy, M.N., Poupon, J.C., Charette, A.B. J. Org. Chem. 74, 8510-8515 (2009).5. Stazi, F., Marcoux, D., Poupon, J.C., Latassa, D., Charette, A.B. Angew. Chem., Int. Ed. 46, 5011-5014 (2007).6. Brouillette, Y., Rombouts, F.J.R., Lubell, W.D. J. Comb. Chem. 8, 117-126 (2006).7. Gisin, B. Helv. Chim. Acta 56, 1476-1482 (1973).8. Marcotte, F.-A., Lubell, W.D. Org. Lett. 4, 2601-2603 (2002).9. Falb, E., Yechezkel, T., Salitra, Y., Gilon, C. J. Pept. Res. 53, 507-517 (1999).269