A general four-step approach to 1,2,3,7,8,8a-hexahydropyrido[4,3-d]pyrimidin-2-ones via Staudinger/intramolecular aza-Wittig reaction of 5-acyl-4-(β-azidoalkyl)-1,2,3,4-tetrahydropyrimidin-2-ones promoted by PPh3 was developed. Synthesis of the starting pyrimidinones included preparation of 3-azidoaldehydes by the addition of hydrazoic acid to α,β-unsaturated aldehydes, transformation of 3-azidoaldehydes into N-[(3-azido-1-tosyl)alkyl]ureas followed by the reaction with 1,3-diketone enolates and dehydration of the resulting products under acidic conditions.
A Novel Access to Pyrido[4,3-d]pyrimidine Scaffold
Published: 30 October 2015 by MDPI AG in The 19th International Electronic Conference on Synthetic Organic Chemistry session General Organic Synthesis
Keywords: Pyrido[4,3-d]pyrimidines; Azidoaldehydes; Tetrahydropyrimidines; Amidoalkylation; Staudinger Reaction; aza-Wittig Reaction