137834-59-4

Upstream product

• 144735-15-9 5-azido-2-methylbenzaldehyde 
• 2840-04-2 5-amino-2-methylbenzoic acid 
• 1975-52-6 5-nitro-o-toluic acid 
• 137834-51-6 ethyl 2-methyl-α,5-bis<(triphenylphosphoranylidene)amino>cinnamate 
• 111437-10-6 3-(hydroxymethyl)-4-methylaniline 
• 622-58-2 p-Tolylisocyanate 
• 137834-61-8 C₄₄H₃₇N₂O₂P 

Relevant academic research and scientific papers

Reactivity and Synthetic Applications of Bis(iminophosphoranes). One-Pot Preparation of Pyridoquinazolines and Benzonaphthyridines

Aza-Wittig reaction of bis(iminophosphorane) 4 with 2 equiv of isocyanate leads directly to pyridoquinazolines 5.Iminophosphoranes 8, available from 4 and 1 equiv of the appropriate isocyanate, react either with 1 equiv of isocyanate or ketene to give pyridoquinazolines 9 or benzonaphthyridines 10, respectively.Bis(iminophosphorane) 4 by sequential treatment with aldehydes and isocyanates yielded 2,3-dihydropyridoquinazolines 17.

One pot preparation of pyrido[2,3,4-de] quinazolines and benzo[de][1,6] naphthyridines by a consecutive process involving an aza-Wittig/ electrocyclic ring-closure/heterocumulene-mediated annelation or intramolecular Diels-Alder cycloaddition sequence

Aza Wittig-type reaction of bis(iminophosphorane)1 with one mole of isocyanate leads to the iminophosphoranes 5 which by treatment with a second mole of isocyanate afforded pyrido[2,3,4-de]quinazolines 6. Similarly, reaction with ketenes leads to the formation of benzo[de][1,6] naphthyridines 9. Direct conversion 1→6 and 1→9 were achieved using two moles of isocyanate or ketene respectively.