N-(ω-carbalkoxyalkyl)ureas and their cyclic derivatives. IV. The synthesis of N-(ω)-carboxyalkyl)-5,6-dihydrouracils from N-(β-carbomethoxyethyl)-N'-(ω-carboxyalkyl)urea
N-(ω-carbalkoxyalkyl)ureas and their cyclic derivatives. IV. The synthesis of N-(ω)-carboxyalkyl)-5,6-dihydrouracils from N-(β-carbomethoxyethyl)-N'-(ω-carboxyalkyl)urea