ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Efficient and library-friendly synthesis of 4-N-substituted 6-bromopyrido[2,3-d]pyrimidines under microwave irradiation
Ya-Quan Sun, Chao-Yang Zong, Jin-Yu Ji, and Qing Han
Yancheng Teachers University, Yancheng, People’s Republic of China
Abstract: In this paper, a novel synthetic method for 4-N-substituted 6-bromopyrido[2,3-d]pyrimidines was reported. Starting from 2-aminonicotinonitrile, following by bromination of aromatic ring, condensation, cyclization, and Dimroth rearrangement, a series of 21 new pyrido[2,3-d]pyrimidine derivatives was prepared in high yields (up to 98%). In the last two steps, microwave irradiation was used. The structures of synthesized compounds were determined by NMR, IR, and HRMS techniques. The results showed that application of microwave irradiation has a beneficial effect for the preparation of desired products, as it is simple and efficient method for improving the yields and reducing the formation of undesirable by-products.
Keywords: Pyrido[2,3-d]pyrimidines ; Dimroth rearrangement ; Microwave-assisted synthesis ; Organic synthesis
Full paper is available at www.springerlink.com.
Chemical Papers 72 (12) 2965–2972 (2018)