Direct Conversion of N-acetyl-d-glucosamine to N-containing Heterocyclic Compounds 3-Acetamidofuran and 3-Acetamido-5-acetyl Furan

Abstract

Effectual waste utilization from plant as well as marine biomass has gained tremendous importance with reference to sustainability. The valorization of marine biomass produces value added compounds containing not only C, H, O but also renewable N atom in the skeleton which widens the scope for its exploration which may prove to be economically bene cial to the society. Heterogeneous catalytic transformation of marine biomass i.e. N-acetyl glucosamine (NAG) to N-substituted aromatic heterocyclic is reported for the very rst time. Cost effective and stable metal oxide catalysts were deployed for the transformation. Catalyst screening study showed that La 2 O 3 was found to be an excellent catalyst for N-acetyl glucosamine (NAG) dehydration which mainly produced 3-acetamidofuran (3AF). The physicochemical properties of the metal oxide catalyst were investigated by various techniques such as XRD, FTIR, MeOH-FTIR, TPD, SEM, N 2 sorption studies and HR-TEM analysis for structure activity relationship. The effect of various reaction parameters such as catalyst concentration, reaction temperature, reaction time and solvent effect on dehydration of N-acetyl glucosamine has been studied in detail for higher yields. The results revealed that the presence of weak basic sites which are Brønsted in nature and nano pores present on the surface were responsible for improved dehydration of the chitin biomass to selectively yield 3-acetamidofuran (3AF). La 2 O 3 catalyst showed optimum 50% 3AF yield from N-Acetyl glucosamine at 180 ºC in 3h. E cacious exploitation of marine biomass to value added chemicals using heterogeneous catalyst through simple route and easy separation of N-substituted heterocyclic aromatics is the most innovative aspect of the current study. Thus, utilization of heterogeneous catalyst and renewable biomass as a raw material indicates a transition towards more sustainable and greener approach. Statement Of NoveltyAs marine biomass is abundantly available on valorization widens its scope for production of value added products and platform chemicals. As far as sustainability and green synthesis is concerned we report for the rst time dehydration of NAG to renewable N-containing furan derivatives by heterogeneous catalyst without use of any additives, ionic liquids or boron compounds. The catalyst showed high stability, easy separation and excellent recyclability upto 5 cycles. The co-operative effect of Brønsted basicity and nanopores on the catalyst play vital role in (100 %) NAG conversion to yield 50 % 3AF and 20 % 3A5AF. 3AF and 3A5AF may nd application as precursors for the synthesis of naturally occurring antibiotic and antitumor drug proximycin A, B and C, amino sugars, pyridine derivatives etc.

Catalytic conversion of chitin-based biomass to nitrogen-containing chemicals

“…3AF and 3A5AF were identified as the major products with 50% and 21% yields in dioxane under optimal conditions. 103 La 2 O 3 displayed a nano-pore structure and acted as a weak Brønsted base, which conducted the dehydration pathway to the 3AF. It was regenerated after successive filtration, wash, dry and calcination.…”

Conversion of N‐Acetylglucosamine to 3‐Acetamido‐5‐Acetylfuran over Al‐Exchanged Montmorillonite

“…Shaikh et al reported that lanthanum oxide catalyzed the conversion of NAG to 3A5AF as a heterogeneous catalyst. [9] 3A5AF formation from NAG proceeds via ring opening of NAG, formation of a five-membered ring, and dehydration. [7] Chloride ion catalyzes the ring opening of NAG and formation of the five-membered ring, [7] as well as the subsequent dehydration.…”

“…Shaikh et al. reported that lanthanum oxide catalyzed the conversion of NAG to 3A5AF as a heterogeneous catalyst [9] . 3A5AF formation from NAG proceeds via ring opening of NAG, formation of a five‐membered ring, and dehydration [7] .…”