The Reaction of Organic Halides With Piperidine. Ii. Certain Alpha-Bromo-Beta-Ketonic Esters

A Regioselective Approach to 5-Substituted-3-amino-1,2,4-triazines

“…However, treatment of 7 with morpholine (4.1 equiv) in THF at 67 °C for 48 h only afforded a 5:1 mixture of keto aminal 11 and mono-morpholinated ketone 12 (Scheme 4) . Formation of the reduced product 12 could be minimized (≤10 mol %) if the reaction was carried out at lower temperature (45−50 °C) and longer time (96 h). Similar results were obtained with N,N -dimethylamine (2 M solution in THF) or N -methylpiperazine.…”

A Quantitative Study of the So-Called “Positive Halogen” in Ketones and Esters

“…Many cases are known in which halogen, especially when in the alphaposition to one or more carbonyl groups, undergoes replacement by hydrogen in the presence of ammonia (1), amines (2), hydrazine (3), alcoholic alkalies (4), organometallic compounds (5), or halogen acids (6). In each such case the product possesses more or less active hydrogen in the place of the halogen.…”

New Synthetic Routes to Δ2-Pyrazolin-5-ones

“…(a) Stable analogs of the intermediate 14 have been isolated by other workers (10). (b) The intermediate 14 can be diverted to an alternative product, 4-hydroxy-I-methyl-3,5-diphenylpyrazole (17), if Z -is a poorer leaving group than Br-. Treatment of 12b with methylhydrazine gives 17 in 92% yield (3).…”