A new Vilsmeier reagent mediated one-pot reaction using 5-(2-chloroacetylamino)pyrazoles as the starting material was developed for the efficient synthesis of 6-[(formyloxy)methyl]-1H-pyrazolo[3,4-d]pyrimidine. This new multiple tandem reactions involving Vilsmeier-Haack reaction, Morgan-Walls reaction, sequential elimination, substitution reaction, and final hydrolysis reaction efficiently afforded formyloxymethyl pyrazolo[3,4-d]pyrimidine products in good yields.Morgan-Walls cyclization reaction, sequential elimination, substitution reaction, and hydrolysis for synthesis of the pyrazole fused pyrimidine derivatives via a tandem multiple reaction. 14,16Pyrimidines fused with a heterocycle such as furo-, 17 pyrazolo-, 18 pyrrolo-, 19 pyridopyrazolo-, 20 and pyrazolotriazolo-pyrimidine 21 are important classes of compounds and also currently of interest to the pharmaceutical industry due to their

In this study, a Vilsmeier-Haack reagent-promoted formyloxylation of α-chloro-N-arylacetamides by formamide was developed. The reaction successfully provided the desired α-formyloxy-N-arylacetamides 4 and 7a-n in moderate to excellent yields (70-96%) by use of 3.0 equivalents of PBr 3 at 80-90 C and was applicable to substrates bearing electron-donating or withdrawing groups at the aryl moiety.For α-chloro-N-(naphthalenyl)acetamide (8a), α-chloro-N-(quinolin-8-yl)acetamide (8b), and α-chloro-N-(thiazol-2-yl)acetamide (8c) possessing the α-chloro group, the reaction also provided the desired formyloxylated products 9a-c in 70-87% yields. A plausible mechanism was proposed through the activation of α-chloroacetamide by Vilsmeier-Haack reagent to account for the new transformation.

No abstract

A convenient synthetic method for N‐arylformamide derivatives was successfully developed by reacting α‐iodo‐N‐arylacetamides with formamide. This method was applicable to α‐iodo‐N‐arylacetamide substrates bearing electron‐donating or electron‐withdrawing groups, N‐(benzo[d][1,3]dioxol‐5‐yl)‐2‐iodoacetamide, 2‐iodo‐N‐(pyridin‐2‐yl)acetamide, and 2‐iodo‐N‐(naphthalen‐4‐yl)acetamide to give the corresponding N‐arylformamides in moderate to excellent yields (65–94%). A plausible mechanism was proposed to account for the new transformation.