2,4-Dichloropyrido[2,3-d]pyrimidine

Selective disubstitution of 2,4-dichloropyrido[2,3-d]pyrimidine with various nucleophiles was investigated by Lavecchia et al. Suzuki and Stille cross-coupling reactions on monosubstituted compound 4-tert-butylamino-2-chloro-pyrido[2,3-d]pyrimidine were performed in high yields. ,4-dichloropyrido[2,3-d]pyrimidine was easily substituted at position 4 with different nucleophiles. This position was more reactive than position 2, as in simple pyrimidinic systems. 2,4-dichloropyrido[2,3-d]pyrimidine 3 was prepared from 2-aminonicotinic acid 1 via 2,4-dihydroxypyrido[2,3-d]pyrimidine 2 following Robin and Hitchings method.

2,4-dichloropyrido[2,3-d]pyrimidine 3 was prepared from 2-aminonicotinic acid 1 via 2,4-dihydroxypyrido[2,3-d]pyrimidine 2 following Robin and Hitchings method[1].

[1] G. Lavecchia, G. Guillaumet, S. Berteina-Raboin. “Selective bifunctionalization of pyrido[2,3-d]pyrimidines in positions 2 and 4 by SNAr and palladium-catalyzed coupling reactions.” Tetrahedron Letters 46 35 (2005): Pages 5851-5855.