Domain: Heterocyclic synthesis

Reaction of (E)-ethyl N-(3-cyano-4,5-diphenylfuran-2-yl)formimidate with hydrazine hydrate in ethanol under reflux affords a compound A. Subsequent condensation of this compound with benzaldehyde in ethanol under reflux yields compound B, followed by cyclization with acetic anhydride under reflux, yields the major product X.

What is the molecular weight of product X?

Grading rubric:
criterion: Identifies Step 1 (hydrazine hydrate, ethanol, reflux) as cyclocondensation of the \(\text{(E)-ethyl N-(3-cyano-4,5-diphenylfuran-2-yl)formimidate}\) 
weight: 10
criterion: States compound A as \(\text{4-imino-5,6-diphenylfuro[2,3-d]pyrimidin-3(4H)-amine.}\) 
weight: 20
criterion: States the compound B as \(\text{ (E)-N-benzylidene-4-imino-5,6-diphenylfuro[2,3-d]pyrimidin-3(4H)-amine.}\)
weight: 20
criterion: Correctly Identifies Step 3 (acetic anhydride, reflux) as intramolecular cyclization
weight: 10
criterion: States the final product X as \(\text{2,8,9-triphenylfuro[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine}\).
weight: 20
criterion: Correctly determine the molecular weight of compound X as 388.43 g/mol
weight: 20

Answer:
388.43 g/mol